The accurate calculation and simulation of solar cells surface reflectance is one of the most important steps in solar cells numerical simulation.The generation profile not only determines the theoretical maximum short circuit current Jsc,but also has influence on the following semiconductor device simulation.This paper focuses on the theoretical calculation and numerical simulation on the surface reflectance of solar cells pyramids texture,via ray-tracing program Sunrays.The optimum thickness of AR coating,silicon nitride,on pyramids texture has also been optimized by ray tracing simulation.Results show that the simulated reflectance curves fit the measured curves to an acceptable good level,and the optimum thickness of nitride coating with 2.0 refractive index at 632nm wavelength is around 75nm.