To address the issues of low efficiency and poor economic performance of dredge pump impellers during engineering operations such as channel dredging and lake or river desilting, the inverse design method was introduced into the performance design of dredge pump blades and study on the influence of different blade loading distributions on the hydrodynamic characteristics of a dredge pump was carried out in this paper. Four configurations with different blade loading distributions were established as follows: load-front of shroud and hub (or the original pump design), load-front of shroud and load-behind of hub, load-behind of shroud and load-front of hub, load-behind of shroud and hub. Computational fluid dynamics (CFD) analysis was used to investigate the influence mechanisms of different blade loading distributions on hydrodynamic performance, including pump lift, efficiency, flow field distribution and blade surface pressure distributions. The research results indicate that the third blade loading configuration, i.e., the load-behind of shroud and load-front of hub, can most effectively improve the original pump design′s head and efficiency. This is because it enhances the pressure difference between the blade pressure surface and the suction face. Moreover, it eliminates the low-speed region that existed in the original design at the mid-channel position, resulting in smoother fluid flow within the channel. Compared with the original design, the pump head is increased by 2.61 m and the efficiency is improved by 2.47% at the design point. The research results can provide a theoretical reference for the optimization design of dredge pump blades and promote its application in industries.