The Thai team was a mixture of full national and SEA Games (U23) players, led by goalkeeper Sinthaweechai Hathairattanakool, Adul Lasoh, Adisak Kraisorn and Teerathorn Bunmathan.
Thailand went ahead after 16 minutes when Pokklao Anan's long-range shot found the back of the net.
Seven minutes later, Buriram United striker Adisak Kraisorn made it 2-0 from close range.
China's Wang Yong Po cut the deficit to 2-1 in the 32nd minute when he beat Sinthaweechai from the spot.
Six minutes after the interval, Adisak restored a two-goal lead for Thailand with a close-range strike.
It was almost one-way traffic as the Chinese players seemed to lack ambition.
On the hour, Chanathip Songkrasin made it 4-1 and Saruwut Masuk completed the rout late on.
Kiatisak, who is coach of the SEA Games team, was recently appointed acting national coach after German coach Winfried Schaefer parted company with the Football Association of Thailand.
After his appointment, he said he did not want to continue as national team coach.