The research progress of photoinitiatios that used in UV-LED curing system was reviewed, which including traditional photoinitiators and their derivatives (thioxanenones, diphenylmethyl ketones and acylphosphine oxides), photoinitiators of new groups (carbazolidyl, naphthalimide, phenazinyl, phenylmalinyl, imidazolidyl and triazinyl) and macromolecular photoinitiators. The stability of photoinitiator can be improved through the modification of traditional photoinitiator and synthesis of macromolecular photoinitiator. The absorption wavelength of the new photoinitiator has a good match with the emission wavelength of UV-LED curing, while this kind of photoinitiator often needs auxiliary agent. Furthermore, the influence of oxygen inhibition on photocuring system is described, the shortcomings of photoinitiators are pointed out and the development and the application of photoinitiators in the future is prospected