The invention provides a method for filtration-assisted purification of acidolysis solution obtained in the process of decomposing phosphorite by using nitric acid. The method comprises the following steps of: adding a filtration aid into the acidolysis solution obtained in the process of decomposing the phosphorite by using the nitric acid; and filtering after uniform stirring to remove acid non-soluble substances and organic floats in the acidolysis solution, wherein the filtrate is purified acidolysis solution. According to the invention, the acid non-soluble substances and the organic floats in the acidolysis solution are thoroughly separated, the removal ratio of suspended substances is high and reaches over 99 percent, and the suspended substance content of the purified acidolysis solution is below 100 mg/L.