visa free entry business purpose

hi all,

I am planning to go to canton fair next month in Guangzhou.
I will arrive at 23/04 at 08.55 and will leave china 25/04 at 20.05h
My ticket is as followed:
Belgium-hongkong-guanghzou-vietnam-hk-belgium

Can the visa free entry be used for going to canton trade fair ? normally I apply for a m-type

Thanks for your help