A method for preparing a selective emitter solar cell, comprising: etching first regions and second regions of a surface of a semiconductor substrate , to form a textured surface with a plurality of protrusions on the first regions and the second regions of the surface of the semiconductor substrate , wherein each of the plurality of protrusions has a cross-sectional shape of trapezoidal or trapezoid-like in a thickness direction of the semiconductor substrate ; characterized by further comprising: performing a diffusion treatment on at least part of the plurality of protrusions to form a first doped layer , and forming a first oxide layer above the first regions , wherein the first doped layer comprises a P-type doping element or an N-type doping element; re-etching the surface of the semiconductor substrate by using the first oxide layer as a mask, to etch each of the plurality of protrusions on the second regions to form a pyramid structure , such that the first doped layer on the second regions is etched to form a second doped layer with a doping concentration lower than a doping concentration of the first doped layer ; and removing the first oxide layer to retain the first doped layer on the first regions , and providing the selective emitter including the first doped layer on the first regions and the second doped layer on the second regions . etching first regions and second regions of a surface of a semiconductor substrate , to form a textured surface with a plurality of protrusions on the first regions and the second regions of the surface of the semiconductor substrate , wherein each of the plurality of protrusions has a cross-sectional shape of trapezoidal or trapezoid-like in a thickness direction of the semiconductor substrate ; characterized by further comprising: performing a diffusion treatment on at least part of the plurality of protrusions to form a first doped layer , and forming a first oxide layer above the first regions , wherein the first doped layer comprises a P-type doping element or an N-type doping element; re-etching the surface of the semiconductor substrate by using the first oxide layer as a mask, to etch each of the plurality of protrusions on the second regions to form a pyramid structure , such that the first doped layer on the second regions is etched to form a second doped layer with a doping concentration lower than a doping concentration of the first doped layer ; and removing the first oxide layer to retain the first doped layer on the first regions , and providing the selective emitter including the first doped layer on the first regions and the second doped layer on the second regions . performing a diffusion treatment on at least part of the plurality of protrusions to form a first doped layer , and forming a first oxide layer above the first regions , wherein the first doped layer comprises a P-type doping element or an N-type doping element; re-etching the surface of the semiconductor substrate by using the first oxide layer as a mask, to etch each of the plurality of protrusions on the second regions to form a pyramid structure , such that the first doped layer on the second regions is etched to form a second doped layer with a doping concentration lower than a doping concentration of the first doped layer ; and removing the first oxide layer to retain the first doped layer on the first regions , and providing the selective emitter including the first doped layer on the first regions and the second doped layer on the second regions . <EOS>