To solve the problem caused by larger-fluctuation river of environmental protection dredging,the paper takes the environmental dredging project of Shanmei reservoir as an example to summarize the way of choosing reasonable dredging time,adopting the proper dredging equipment used for the specific water level,and using the natural drying of solar energy to reduce the water content of the sediment,and thus improve the efficiency and save the cost,to provide experience for the subsequent engineering.