The invention provides a method for reinforcing and fixing endogenous phosphorus on eutrophic water body bottom mud. The method comprises the following steps that 1, water purification plant sludge is filtered with an iron screen, dried, crushed and then sieved by a 100-mesh sieve to obtain treated water purification plant sludge; 2, anhydrous calcium chloride powder sieved by the 100-mesh sieve is doped into the treated water purification plant sludge, and the materials are mixed to be uniform by a stirrer to obtain a mixed material; 3, the mixed material is fired to obtain an endogenous phosphorus curing material; 4, the endogenous phosphorus curing material is tiled on a surface layer of the remediated eutrophic water body bottom mud; 5, corbicula fluminea is introduced; 6, the endogenous phosphorus curing material is uniformly laid on the surface layer of the remediated eutrophic water body bottom mud again, and then the step of reinforcing and fixing the endogenous phosphorus on the eutrophic water body bottom mud is completed. According to the method, the bottom mud interior microenvironment can be changed, a space and a state in which anaerobism and aerobism alternatively exist are formed, and mutual transformation between the endogenous phosphorus forms is reinforced.