Hi, I am a Taiwanese now with non b(teacher) but expire on 16 Mar which is next Wednesday. My job agent had promised to make 1 year visa but they can't make sure to make it before the day expired. I have too much problem with them that I don't want to work with them anymore that I want to make a tourist visa in Viemtiane by myself. I have 3 tourist on the passport and the last one with a stamp "next time will be refused". If I go to Viemtiane can I get tourist visa successfully?

That is unclear. You might get refused or get a single entry tourist visa instead of a double entry. It would depend on how long ago you got your last tourist visa.

But with such stamp saying next time you will be denied (if you got that stamp from Vientianne) applying in Phnom Phen might be a better idea.