To make water in urban rivers flowing and improve water quality, an eco-gate pump unit which uses plate gate as a carrier was designed and developed based on computational fluid dynamics method and the model test in this paper. Firstly, the bidirectional operation energy performance of eco-gate pump was verified by the model test. The results showed that the numerical simulation results were consistent with the model test results with an error of ±2% at the optimum operating condition both in the pumping mode and the powering mode, which verified the reliability and accuracy of numerical stimulation. The major sources of error associated with the power losses were due to the fact that the blade tip leakage and the blade deflection were not considered in computational fluid dynamics simulation. The thickened blade edges also contributed to the differences. On this basis, different schemes of runner blade’s setting angles, blade number, blade lean angle, bulb body’s length, and shoulder profile line were designed, and their influences on eco-gate pump’s performance were analyzed to choose the best runner type and bulb body’s profile line through the computational fluid dynamics numerical simulations. The numerical results showed that the eco-gate pump had the best hydraulic performance when the blade’s setting angle was = 23°, blade number z = 5, blade’s lean angle a = 0° and bulb body’s shoulder profile line was convex type with length L = 100 mm. The developed pump showed the highest efficiency of 70.95% under the condition of design discharge of 500 L/s and design lift of 1.0 m. Furthermore, the whole flow pattern of the optimized pump was analyzed. Overall, the eco-gate pump presented in this paper can make use of its low-lift pumping function to replenish the target water body more efficient than other similar products. At the same time, it also can utilize the micro-head water energy fully to generate power.