Different from the optical fiber with large core made with traditional technique,optical fiber with large pure quartz core and Fluorine-doped glass cladding is a new structure of large core fiber,it is used mainly in the fields of light energy transfer and light sensing .It is made by POD(plasma outside deposition)technique abroad.As we don′t have the equipments in domestic,we creatively used the rod in tube method to do that,i.e use PCVD(plasma chemical vapor deposition)technique to make F-doped quartz tube,and jacketed a pure quartz rod as the fiber core inside the F-doped quartz tube to form the fiber with the same structure as that from POD technique in high temperature condition by MCVD（modified chemical vapor deposition）technique.Measurements and results show that our products have the same performance with those made abroad.