The invention discloses a preparation method of a selective emitter solar cell, comprising the following steps: providing a silicon wafer for carrying out surface texturization; printing a diffusion permeable membrane on the silicon wafer by a first silk-screen printing plate; covering a non-electrode region by using the diffusion permeable membrane printed by the first silk-screen printing plate, exposing an electrode region to be printed; forming a light diffusion layer for the silicon wafer in the non-electrode light-affected region with the permeable membrane, and forming a heavy diffusion layer in the electrode region without the permeable membrane to be printed; carrying out corrosion for removing peripheral PN nodes, washing the membrane, and removing phosphosilicate glasses; preparing a passivation layer and an antireflection layer; and printing by the printing screen printing plate and sintering to form a back Ag electrode, a back Al-BSF and a front Ag electrode. The preparation method for the selective emitter solar cell provided by the invention adopts one-time diffusion to form the light and heavy doping required by the selective emitter solar cell, thereby reducing one-time high-temperature diffusion process, simplifying processes of the technology, and lowering the cost.