Abstract: To prepare silicon nanowires with good appearance and performance, a metal-assisted chemical etching method was used to deposit Ag particles in the mixed aqueous solution of AgNO₃ and HF in this paper, which was used as the catalyst for the etching reaction, and the silicon nanowires were prepared by etching reaction in the mixed solution of H₂O₂ and HF. By changing the technological parameters in the experiment, including etch reaction time, etch reaction temperature, HF concentration in etch solution and stirring speed in the reaction process, the optimum parameters for preparing excellent silicon nanowires were discussed by means of SEM image analysis. Results show that when the etching reaction time is 1 hour at room temperature and the HF concentration is 4.8 mol/L, the surface morphology of silicon nanowires is the best. Meanwhile, the agitation of etching solution seriously damages the surface morphology of silicon nanowires, which is not conducive to the preparation of excellent silicon nanowires.