On Nov. 16, I will fly from Warsaw to Moscow via Minsk.
I stay in the airport only for 1.5 hours.
I am a Chinese citizen. I have a Russian tourist visa. I have already booked the ticket.
The airline is Belavia.
According to the Belarusian Airlines website:
Is the transit visa needed?
According to the information, obtained from National airport Minsk border guard service:
Those passengers, who travel in transit through Minsk, do not need the Belarusian transit visa, if the following conditions are fulfilled:
passengers have a valid passport and valid documents (national passport and/or visa , etc.) required for entry into the country of destination;
valid single ticket for the entire route to the destination point;
stay in Minsk does not exceed 24 hours and the passenger does not leave the so-called airport transit zone.
Timatic confirms this as well:
So the answer is: no, you do not need a transit visa.
It's a little bit confused, but it seems you might not need one if you stay in the airport, judging by this thread (Oct 2015)
However Belarus does have a transit visa which allows up to 2 days of travel across the country, but I'm assuming that's literally just to go across on your way somewhere else and WikiVoyage seems to go in that direction as well because only the train travel section mentions transit visas while the air travel doesn't. In any case, Chinese citizens are not exempt of visas for Belarus.
If you decide to apply for one anyway just to be safe, you can get one at the airport but you need to send in some documentation ahead of time, at least 3 days before