In order to improve the hydraulic performance of the integrated pump gate, the flow pattern of the inlet and outlet of the pump gate is improved. This paper adopts the SST k-ω turbulence model to numerically calculate the initial scheme of the integrated pump gate, verifies its internal flow pattern through experiments, then adds and optimizes the design of the inlet and outlet horn pipes of the integrated pump gate through orthogonal optimization. The research results conclude that the hydraulic performance of the integrated pump gate is significantly improved after adding the inlet and outlet horn. Under the design flow condition (Qd = 11.5 L/s), the efficiency of the pump gate increased from 60.50% to 67.19%, the head increased from 2.7569 m to 3.1178 m, the hydraulic loss in the inlet channel decreased from 0.064 m to 0.027 m, and the hydraulic loss in the outlet channel decreased from 1.337 m to 1.027 m. The optimized trumpet pipe can improve the inlet conditions of the pump while weakening the vortices in the outlet channel, thus improving the efficiency and safety of the integrated pump gate. The research results of this paper are of reference value for similar projects.