Recreation carrying capacity estimation and predication is an important tool for recreation planning and dynamic management of national park. This paper establishes a system dynamics model for Sanjiangyuan National Park recreation carrying capacity based on the system dynamics simulation software Vensim_PLE, which includes four subsystems, namely resource space, ecological environment, socio-economic, and social-psychological system. Using 2015-2035 as the time interval, this paper sets four scenarios for simulation to estimate trend of each subsystem, providing a reference for the recreation planning and management of Sanjiangyuan National Park. The four scenarios include original scenario, the social-driven scenario, the ecological protection priority scenario, and the coordinated development scenario. Results show:(1) Under the current original scenario, the recreation carrying capacity shows a trend of increasing initially and deceasing afterwards. However, it may face the risk of surpassing the recreation carrying capacity in 2031. Under the social-driven scenario of increasing investment in recreational facilities, the recreation carrying capacity has improved, but the effect of improvement after 2031 will be weak. (2) Under the ecological protection priority scenario, through the improvement of capacity of pollution prevention and control of tourist scale, the recreation carrying capacity has been improved, and the risk of overloading the recreation carrying capacity has been postponed from 2031 to 2033. (3) Under the coordinated development scenario, the ecological environment carrying capacity and the resource space carrying capacity increase slowly, with the highest value among the four scenarios, and the recreation carrying capacity reaches the maximum value. The risk of overloading the recreation carrying capacity extended from 2031 to after 2035. The simulation and prediction of recreation carrying capacity of national park provides a scientific reference for reasonable and timely control, which is conducive to ecological protection and improvement of recreational quality in Sanjiangyuan National Park.