Abstract: Atmospheric environmental impact prediction is a core component of environmental carrying capacity assessment in the planning environmental impact assessment (EIA). Aiming at the problems of insufficient spatial resolution and limited accuracy in simulating multi-source pollution diffusion under complex terrain conditions using traditional single-model predictions, this study takes the planning of an industrial park in western Yunnan as a case to construct a two-tier prediction system of “large-scale rapid screening - refined simulation in key areas”. The study confirms that the application framework of the AERMOD model coupled with high-resolution terrain data can effectively resolve the contradiction between “full-area coverage” and “local accuracy” in the planning EIA. The proposed “source-flow-sink” collaborative control strategy provides a scientific basis for the sustainable development of industrial parks in plateau and mountainous areas.