The invention disclosed an additive for preparing suede on a polycrystalline silicon chip. The invention also provides a suede preparation liquid for preparing suede on a polycrystalline silicon chip, comprising: an acid solution and the aforementioned additive for preparing suede on a polycrystalline silicon chip. The invention also provides a method for preparing suede on a polycrystalline silicon chip, by using which suede can be prepared on the surface of a polycrystalline silicon chip with the foregoing suede preparation liquid.