The effect of different surfactants,such as neopelex(ABS-Na),lauryl sodium sulfate(DS),polyethylene glycol(6000)(PEG(6000)),Tween-80 and their mixtures,on the stability of plating solution,deposition velocity of electroless plating Ni-P-SiC,morphology and performances of Ni-P-SiC composite coating on magnesium alloys was studied.Further,the optimization surfactant for electroless plating Ni-P-SiC composite coating on magnesium alloys was selected.The results show that the surfactants can evidently improve the stability of electroless plating Ni-P-SiC solution,the species of surfactants have an important effect on deposition velocity,the deposition velocity of the plating solution containing neopelex+polyethylene glycol(6000)is the fastest.Based on the surface quality,hardness and anti-corrosion performance of the Ni-P-SiC composite coating,mixture of lauryl sodium sulfate+polyethylene glycol(6000)is selected as the best adaptive surfactant for electroless plating Ni-P-SiC composite coating on magnesium alloys.