I cannot tell you the exact official position (or the N official positions as the case may be) but I can give you some useful personal anecdotal input.
You are extremely unlikely to have any problems at all if you are otherwise sensibly behaved. If you did happen to incur the wrath of the authorities I would not be overly surprised if a statute relating to knife carrying was found to have been breached. It's not something I'd be concerned about personally, see below.
You hear about some very very very bad things happening in China. More than a few of these are probably true. If you do run afoul of the system things can go rather wrong. But, they do generally treat foreigners well enough officially. (I have seen a 'local' man with his hands handcuffed behind him pushed to the ground on a city street by a largish group of um - guys with all the same colour clothes and helmets and matching sticks... and kicked repeatedly in the back. Why I know not. He didn't actually seem to care too much, to my surprise.) Whereas I have given people in authority enough excuse to justify treating me badly and they have instead treated me acceptably well. YMMV.
When I travel overseas on business I often carry one or two pocket knives along with a significant collection of electrical and mechanical tools. When I travel privately the tool collection reduces 'somewhat' but the knives remain. I used to carry a Swiss Army knife but find that an ordinary knife is overall more useful as an "engineering" tool in all sorts of situations. If I really want a screwdriver I usually have one with me. (Or two or three or six :-) ).
The following three paragraphs may seem unnecessary but are relevant to what follows:
My knives are absolutely NOT intended as weapons. When occasion arises I instruct young people what to do with a knife if you are attacked - viz: "Bury it deep in your pocket and make sure nobody knows that you have it - odds are that any one who wishes you physical harm knows how to use a knife better than you do, will probably manage to take it from you and giving them something that may be more liable to kill you than what they have already is probably unwise." But - other people do not know why I carry them.
The two knives I usually carry are metal, folding, single blade. About 3" I think. Neither is spring-open style but both can be seen as borderline 'flick knife' as both are designed to be opened one handed either by a stud on the blade on one which allows the thumb to swing the blade or by pressure on a short behind the hinge blade extension on the other which allows thumb pressure to rotate the blade. Both lock open and have a latch that must be operated to allow them to close. Again one handed with due practice. I practiced with both enough to allow me to withdraw the knife and open it in one motion and to also put it away one handed.
ie the knives are of a type that while useful would be expected to be borderline legal or worse in some countries. They are sharp and pointed and made to be opened as they are taken from a pocket. The blades lock open.
I have travelled extensively in China - 15 visits and 6 months in China in the last 6 years. As well as travelling as a passenger in private cars I have travelled widely by train, taxi, bus and air.
I bought both knives in China. One from a typical city-suburbs grocery store where it was on open display at a counter with maybe a dozen other models. The other from an inner city street market where it was on display with dozens of others among hundreds of sellers of which many would also have been selling knives.
When I fly I check my pockets at check-in to ensure nothing unallowed is carried. I put one or two knives in the outer zipped pocket of my checked in bag and recover them on arrival. They would show easily on XRay or the most causual inspection
The bags are on some occasions inspected and/or xrayed while out of my care. On one occasion I got my bag back last of anyone so that I was last in queue. It did not occur to me that this was not just happenstance :-). On arrival at security / customs I was invited to join half a dozen customs men in a side room and we spent a merry half hour or so looking at everything in all my bags and having me explain what each was. I had a full electronics workshop with me :-). That was during the Olympics at Qingdao (Olympic yachting) and they were 'cautious'. The knives were not treated any different from anything else. (This was an internal non-border airport but these can be treated in much the same way as an international border.)
I have used the knives 'as required' in my China travels. Bag or shoe repair. Various misc tasks.
In Urumqi (far North West China) the Uighur men all carry (I'm told) special curved and decorated knives. These are sold in all shapes and sizes in the shops and I saw groups of men sitting in circles inspecting knives - what they look for in them I did not find out.
I once - stupidly - accidentally failed to place a Swiss Army knife into my checked in luggage and it was found in my bag at boarding security at an inland (non-border) Chinese airport and confiscated. I had no problem at all with that at it was a clear rule violation on my part. They also however confiscated an inkjet cartridge refiller that had 3 x 10mm needles internal to it. I think I could have hurt people more with my fingernails than with the refiller. It had previously passed through several international customs checks and several internal Chinese security checks. I was so annoyed at the complete ludicrousness of the decision and their failure to accept my explanation re prior acceptability that I yelled loudly at the 'customs' man - the only time I've ever done so and an immensely stupid thing to do (and very out of character for me.) He politely stood his ground and I continued to my aircraft. I have no doubt that he would have been within his rights to decide to teach me a lesson and delay my trip while I was subject to more intensive official processes. My point in detailing that occurrence (apart from showing how stupid I can be on (rare :-) ) occasions) is to show that even when I did "try" to carry a knife onto an aircraft and then behaved in a manner which everyone knows may result in 'a delay in your journey', they still behaved politely and properly and ignored my behaviour.
Knives are openly available in many places in China.
Knives carried in checked baggage do not seem to excite them.
Knife carrying noisy idiots at check in may be tolerated.
All the same, don't push your luck too far :-).
Well. Fancy that. The two part all metal one appears to possibly be made in Viet Nam
This is my one:
Larger image here
Rei, Me 5964
But all the websites that I found it in were Vienamese ones such as this one. The ad says "Origin: China". Who can tell?
Rimei Knives Picnic 5964
-Material: Made of low alloy steel with features such as bending, anti-oxidation, high strength and stiffness than conventional steel alloys other.
-Designing: sharp knife Compact foldable knife hidden in the body, decorated with camouflage motifs healthy, strong personality. Empty knife slots include many works prying, this item or any hanging hooks. Is this gadget a perfect fit for picnic trips, to use rapid application in cases of necessity, such as cut fruit, cut trees, wound treatment ...
440C Stainless Steel(56-58HRC)