Abstract: How to choose the direction and proportion of the use of reservoir migrants’ support funds to achieve the maximum efficiency of the use of reservoir migrant support funds is a difficult problem to be solved urgently. Based on the use and implementation effect of reservoir migration support funds in 15 sample counties（cities and districts） in Guangdong Province in 2021, this paper uses the DEA model to calculate the efficiency of reservoir migration support funds. At the same time, environmental factors are taken into account, and the Tobit regression model is used to analyze the environmental factors affecting the efficiency of capital use. The results show that:（1） The efficiency of the use of reservoir resettlement support funds in the sample counties varies greatly, among which the pure technical efficiency value is better, and the scale efficiency has become the main factor affecting the comprehensive efficiency, and it is necessary to optimize the scale allocation to improve investment redundancy；（2） Among the environmental factors affecting the efficiency of capital use, the improvement of the economic development level, urbanization rate and openness of the permanent population in the sample counties contributed to the improvement of the efficiency of the use of reservoir migrants’ support funds, while the added value of the tertiary industry did not significantly promote the efficiency of the use of reservoir migrants’ support funds.