A crystalline silicon solar cell includes a gallium oxide layer in direct contact with a P-type silicon layer in the crystalline silicon solar cell. The gallium oxide layer is arranged on the P-type silicon layer of the crystalline silicon solar cell, negative charges of the gallium oxide layer are used to carry out chemical passivation and field passivation on a surface of the P-type silicon layer, and the number of dangling bonds and minority carriers of silicon atoms on the surface of the P-type silicon layer is reduced, so that a minority carrier recombination rate at the surface of the P-type silicon layer is reduced. In addition, the gallium oxide layer has a relatively wide band gap and an appropriate optical refractive index.