The invention discloses a method for preparing monocrystalline silicon suede, which comprises the following steps of: 1) preparing 0.05 to 0.5 percent rough polishing solution from 45 percent aqueous alkali and deionized water in a thermostat with the temperature of between 75 and 85DEG C; 2) preparing 0.5 to 5 percent analytical pure alkali and 87 to 98.4 percent of deionized water into 45 percent aqueous alkali, and mixing the 45 percent aqueous alkali, 1 to 7 percent analytical pure isopropanol, 0.1 to 1 percent analytical pure sodium silicate and the rest deionized water into alkaline corrosion solution in the thermostat with the temperature of between 75 and 85DEG C; and 3) pre-cleaning a monocrystalline silicon piece for 1 to 6 minutes in the rough polishing solution, taking the monocrystalline silicon piece out, soaking in warm water, reacting for 10 to 30 minutes in the alkaline corrosion solution, taking the monocrystalline silicon piece out, washing with deionized water, anddrying. The prepared monocrystalline silicon suede has small-size and uniform pyramids, the light absorbing capacity of batteries is improved, the suede preparing reaction time is shortened, and the production cost is reduced.