Dynamic prediction and regulation of water resources carrying capacity in lake basin is an important basis and means to maintain lake ecological security and ensure the healthy and sustainable development of economy. In this paper, Chaohu Basin is taken as the research object, and the dynamic prediction technology and the optimal regulation method of experiment of water resources carrying capacity of lake basin based on system dynamics are proposed. Firstly, a simulation and dynamic prediction model of water resources carrying capacity system is constructed with county (city) as the basic unit; then, the multiple counties (cities) are coupled into the whole basin model in space, and the regulation index of quantity and quality elements are selected through sensitivity analysis; finally, the orthogonal design method is used to determine the optimal regulation scheme of water resources carrying capacity. The results show that due to the expansion of industrial scale and the improvement of urbanization, the water resources carrying state value of Chaohu Basin is deteriorating from 2017 to 2050, and it will be overloaded for a long time after 2030. After targeted optimal regulation of influencing elements, it will reach critical or loadable. This study shows that the method proposed in this paper has good application value for promoting the coordinated development of regional socio-economic environment and improving the regional water resources carrying capacity.