I'm a Chinese national, living in Belgium right now. I am thinking of departing from Azerbaijan, then taking a ferry to Turkmenistan, then Uzbekistan and maybe Kyrgyzstan, finally arrive in China.(within central Asian countries preferrablly by train)
For all the countries I would pass through, do I need a normal tourist visa or a transit visa?
Not really. For example, Uzbekistan has a 2x72hr transit visa, but that really doesn't give you time to do much at all. You need to get a tourist visa, and a Letter of Invitation.
It's probably the hardest one to get (although Kazakhstan took me a long time when I was in St Petersburg).
The 'best' resource online for this at present is probably Caravanistan for those countries. They'll tell you exactly what the latest visa requirements are, but essentially, no. That Turkmenistan ferry is notorious for example, for not leaving on time - sometimes waiting a week before it departs, which makes it very, very hard to plan visas around, and would certainly cause you problems even if you could get a 'transit' visa that allowed you to use the ferry.
A great resource for this can be found at Visa requirements for Chinese citizens (Wikipedia has a page like this for every country). On this page, you can see that although Chinese citizens do not need a visa for Azerbaijan to visit up to 30 days, a visa is required for all the other countries on your proposed itinerary.
Similarly, you can find additional information on the following pages:
The only one where a transit type visa is mentioned at all is Turkmenistan, where:
Citizens of all countries have the right to visa-free transit through the international transit area of the Ashgabat Airport.
