Using triarylsulfonium hexafluorophospate salts as cationic photocuring catalysts, the photocuring reaction of Tung oil modified phenolic epoxy resin (TMPE) and bisphenol-A epoxy resin (E-44) was researched. The influence of reactive condition on photocuring rate was investigated with gel percent of the system. Coating structure before and after the photocuring reaction was charactered by FT-IR spectrum.The results show that both of structure and concentration of photo-initiator can influent the photocuring rate of the reactive system, and Omnicat 550 has higher catalytic activity than Omnicat 432 and the photocuring rate is proportional to the concentration of photo-initiator. Except of phenothiazine, the other two photo-sensitizers - anthracene and BPO can promote the initiation of Omnicat 432.Different kinds of epoxy and vinyl ether diluents can make the photocuring rate variety，and the photocuring rate is increased with the concentration of epoxy group in the system．At last, the phenomenon of post-curing of this system is appeared in this system. 