Abstract: The surface passivation of silicon substrate has been studied,and the minority carrier lifetime of silicon substrate wafer along with its influence on the crystalline silicon / amorphous silicon heterojunction（HIT） solar cell has been tested and analyzed.It is found that appropriate HF solution treatment,H-plasma treatment,as well as inserting approximately 3nm intrinsic amorphous silicon layer can significantly improve the minority carrier lifetime of silicon substrate,which can improve the open circuit voltage of HIT solar cell sequentially.By comprehensively optimizing the process of HIT solar cell,the conversion efficiency of 16.75%（Voc=596mV,Jsc=41.605mA/cm2,FF=0.676,AM1.5,25℃） on n-type silicon substrate is obtained.