The invention relates to a method for preparing a crystalline silicon solar cell. The method specifically comprises the following steps of: 1) performing wet texturing, and performing reactive ion etching, passivation and deionization for secondary texturing; and 2) diffusing a silicon chip obtained by the step 1), and sequentially performing edge etching, removal of phosphorosilicate glass, hydrogen passivation, deposition of a silicon nitride film, silk screening of cathode, anode and back aluminum, and sintering. In the method for preparing the crystalline silicon solar cell, the method for prolonging the optical distance of light in crystalline silicon and reducing light reflection loss is mainly provided; and the crystalline silicon chip prepared by the method provided by the invention has relatively lower surface reflectivity, and the hydrogen passivation performed before the deposition of the silicon nitride film can reduce silicon dangling bonds, form Si-H, reduce surface states, increase short-circuit current and fulfill the aim of improving the conversion efficiency.