The invention belongs to the technical field of sugarcane sugar production, relates to a lime method sugar clarification method. The clarification method comprises the following steps: step 1, preliming; 2, heating once; 3, degrading starch by amylase; 4, main liming; 5, reheating. As compared to that prior art, the invention skillfully gelatinizes the starch in the primary sugarcane juice by one-time heating, and the residence time of the secondary cane juice is prolonged to let the amylase exert its activity, the adverse effects of starch on sugar production is excluded, then the natural amylase is inactivated by reheating to avoid residual amylase in the final product. In addition, the reaction between phosphoric acid and lime milk is enhanced by prolonging the residence time of the pressed mixed juice to improve the clarification process and the filtration performance of the mud juice, and to avoid the scale formation in the evaporation tank and the sugar boiling tank caused by thelag of acid-base reaction.