The invention provides a method for preparing tetrabasic lead sulfate. The method comprises the following steps: S10. impurities are removed from a lead acetate stock solution, so as to obtain a lead acetate solution; S20. the lead acetate solution is mixed with an alkaline solution under a heated condition, and lead oxide is obtained after filtering; S30. the lead oxide is mixed with sulfuric acid, filtering is carried out after reaction, and ball milling is carried out after sintering to obtain the tetrabasic lead sulfate. The method provided by the invention has the advantages of simple and controllable processes, high product purity (above 99 percent), and uniform and controllable particle sizes; moreover, according to the method, the lead acetate serves as the initiator to prepare the high-purity tetrabasic lead sulfate, and multiple batches of measurements of the tetrabasic lead sulfate show that the contents of iron element and barium element, which are the impurities significantly affecting the battery performance, are below 20 ppm and below 2 ppm respectively.