Thai people are generally not allowed to apply for a work visa directly after entering China visa free.
According to the China Thailand Mutual Visa Exemption Agreement for Ordinary Passport Holders, starting from March 1, 2024, Chinese nationals holding official ordinary passports, ordinary passport holders, and Thai nationals holding ordinary passports can enter each other’s countries without a visa, with a single stay of no more than 30 days and a cumulative stay of no more than 90 days per 180 days.
For activities that require prior approval to enter the other country for work, study, news reporting, settlement, etc., and for those who intend to stay in the other country for more than 30 days, they must obtain the corresponding visa before entering the other country.
If Thai people want to work in China, they need to apply for a work visa in advance at the Chinese embassy or consulate in Thailand or the visa application center.