In order to improve the durability of concrete used in water conservancy engineering and meet the application requirements of concrete under complex working conditions, research on the application of polypropylene fiber concrete in water conservancy projects has been conducted through benchmark mix proportion design tests, single-factor tests of polypropylene fibers, and single-factor tests of polycarboxylate superplasticizer. The test results show that adding polypropylene fibers to concrete can improve the mechanical properties, impermeability and wear resistance of concrete, but it will reduce the fluidity of concrete. Based on the comprehensive test results, it is concluded that the optimal dosage of polypropylene fibers is 0.75 kg/m³. By increasing the dosage of polycarboxylate superplasticizer to counteract the reduction in the fluidity of concrete caused by the addition of polypropylene fibers and improve the workability of concrete, the experiment concluded that the optimal dosage of polycarboxylate superplasticizer is 0.55 kg/m³. The optimal mix ratio of polypropylene fiber concrete was applied to the gate slot working condition of water conservancy projects to test the performance. The test results show that the slump of polypropylene concrete is 140 mm, the 28-day compressive strength is 53.15 MPa, the average water seepage height is 55 mm, and the maximum water seepage pressure is 3.25 MPa. The wear per unit area is 0.50 kg/m², which meets the requirements of engineering applications.