Abstract: The essential situation of injector SFC in Heavy Ion Research Facility at Lanzhou（HIRFL）is introduced brifly.In order to satisfy the requirements of Radioactive Ion Beam Line at Lanzhou（RIBLL）and Cooling Storage Ring（CSR）for HIRFL,a new vacuum chamber has been made.The double vacuum chamber technology has been used.As aresult,the pressure of 8×10^-6 Pa pressure on the me-dian plane in the cyclotron is obtain ed.