A selective emitter (SE) solar cell fabrication process using Si3N4mask layer is designed and the fabrication parameters are optimized. The first doping parameters of the SE solar cell are the same as the best doping parameters of normal solar cells. The parameters of pre-doping concentration, diffuse time and temperature are simulated and analyzed with SILVACO software. The simulation results show that the spectrum response performance enhances first then decreases with the pre-doping concentration increasing. And the spectrum response performance decreases with the increasing diffusing time and temperature. The process parameters can be chosen as: pre-doping concentration of 1×109 cm-3, diffuse time of 5min and doping diffuse temperature of 800℃.