In order to analyze the process sensit ivity of the quantum efficiency in silicon-based pinned photodiode (PPD) more c omprehensively and systematically,based on the finite difference time domain num erical simulation by taking account of surface Shockley-Read-Hall (SRH) recombination rate model ,the variation characteristics of the visible spectral quantum efficiency and the corresponding physical mechanism s are both studied under different process conditions of P⁺-type surface layer and P-type epitaxial ( EPI) layer.Results show that the quantum efficiency of the wavelength under 500nm decreases with both the SRH re combination rate increases and the top position of PPD barrier region moves down,which can be induced by the in creases ion implant dose and energy of P⁺-type surface layer respectively,and the reduction of the barrier region width further induced by the latter one can make the quantum efficiency attenuation extend to the wavelength of 650nm.The quantum efficiency of the wavelength between 500nm and 750nm decreases with the bottom position of P PD barrier region moves up, which can be induced by the increase doping concentration in P-type EPI layer.The quantum efficiency of the wavelength above 700nm promotes and tends to be saturation due to the reduction of photo charges in the strong SRH recombination region in substrate,which can be induced by the increase EPI thickness.The significant wavelength differences presented in the influence of P-type process conditions on the quantum efficiency can be fundamentally attributed to the intense dependence of photon absorption depth on the incident wavelength in silicon-based material.