Transporting high-concentration,large-grain rock mixtures via mud pumps in heavy cutter suction dredgers’ rock excavation condition,impeller geometric parameters significantly constrain performance and pose a high risk of clogging.A study is conducted on the impellers of“Tiankun”dredger’s underwater and onboard mud pumps.By applying the relationship formulas between impeller parameters and medium characteristics,combined with numerical simulation analysis of flow fields and external performance,supplemented by model pump tests for validation,the effects of impeller outlet widening and blade optimization are investigated.An analysis of the head,power,and efficiency of the impeller before and after optimization is conducted.The rotational speeds of the underwater and onboard mud pump impellers are determined.The results demonstrate that increasing the impeller outlet width by 10% and optimizing the blade design improve the flow passing diameter by over 5% and the flow volume by more than 15%,significantly enhancing the passage capability for large particles.The total power consumption of the optimized impeller meets the requirements for simultaneous operation of high-power equipment such as cutters,water pumps,and mud pumps.This optimization solution provides parameters and technical pathways for impeller design and serves as a reference for improving the performance of similar equipment in complex solid-liquid conditions.