Since the first lasing in March 2005 in CAEP,the FEL-THz facility has been updated,the former thermionic cathode injector has been replaced by a high brightness photo-cathode injector.The facility mainly consists of a 4.5 cells photo-cathode RF-gun injector,a hybrid undulator and the optical oscillator cavity.The parameters are as followed: number of undulator periods:44;the peak value of the undulator:0.49 T;the good aperture:6 mm;the cathode material:Cs2Te;the quadruple light was used;the width of the driving laser:12 ps;the quantum efficiency:about 1%.The commissioning of the injector has been finished;the electron energy of the injector has been measured and it is about 8 MeV with the energy spread about 1%,and the electron beam normalized emittance about 9 πmm.mrad.The charge is about 100 pC and up to 1nC per micro-pulse,the repetition rate is 54.167 MHz.The calculated wavelength of the light is about 125 micron.At present,the spontaneous emission experiment is undertaking. Since the first lasing in March 2005 in CAEP, the FEL-THz facility has been updated, the former thermionic cathode injector has been replaced by a high brightness photo-cathode injector. The facility mainly consists of a 4.5 cells photo-cathode RF-gun injector, a hybrid undulator and the optical oscillator cavity. The parameters are followed: number of undulator periods: 44; the peak value of the undulator: 0.49 T; the good aperture: 6 mm; the cathode material: Cs2Te; the quadruple light the used energy of the injector has been finished; the electron energy of the injector has been measured and it is about 8 MeV with the energy spread about 1%, and the electron beam normalized emittance about 9 πmm.mrad. The charge is about 100 pC and up to 1nC per micro-pulse, the repetition rate is 54.167 MHz. The calculated wavelength of the light is about 125 micron. At present , the spontaneous emission experiment is undertaking.