The surface of TC4 titanium alloy was cladding modified by fiber laser,and the effect of powder feeding rate on cladding process and cladding layer performance was studied. The distribution morphology of the heating powder in space was photographed using high speed camera system,the cross section morphology of the cladding layer was observed using optical microscope,the nitrogen content of the cladding layer was detected using EDS and the cross section microhardness of the cladding layer was measured. The experimental results show that the powder absorbs a little laser energy when the powder feeding rate is low,the molten pool is large,and the cladding layer is wide and shallow. The powder absorbs a lot of laser energy when the powder feeding rate is high,the molten pool is small,and the cladding layer is narrow and deep. When the powder feeding rate is high,the nitrogen content and microhardness of the cladding layer are uniformly distributed without obvious gradient. With the increase of powder feeding rate,the microhardness of the cladding layer increases,and stabilizes at about 9. 3 GPa.