When an optical fiber using silica glass is used for transmitting UV rays,the various color centers are produced,such colors cause structural defects in the silica glass,which decrease the transmittance of silica glass fiber.In order to improve resistance of silica glass fiber to UV irradiation,a UV immunity technique is presented in our fiber optics laboratory.The technique of fabricating a UV fiber using silica glass is based on two effects of previous UV irradiation and heat treatment,which is called UV immunity technique of manufacturing UV fiber.The UV irradiation is implemented in the preform of silica glass fiber,and the heat treatment is finished in drawing fiber process.Then high-performace UV fiber is obtained.Finally,UV fibers are tested,from these tested results,it is seen that UV fibers fabricated by the UV immunity technique show better transmission characteristics during transmitting UV light,and that the reduction of the transmission loss of 0.4-0.8 dB for per meter from 350 nm to 400 nm is obtained.