The invention provides a method for manufacturing citric acid by a cane fermentation method. In the method of the invention, the cane sugar is utilized as the carbon source, and inorganic and organic nitrogen sources and various nutrient elements are added for fermentation to manufacture the citric acid. The quality of the fermentation liquid is obviously improved; the metabolic rate of the saccharic acid is improved; the fermentation cycle is shortened; the production cost is minimized; the acidity of citric acid in the fermentation liquid can reach 11-14%; the fermentation cycle is 70-85 hours; the conversion percent of the saccharic acid is greater than 89%. The invention has positive meanings to promote the diversification of the production raw materials of the citric acid and in particular the development of foreign markets.