Atmospheric pollutant VOCs are negative products brought about by economic development and urbanization. They are mainly produced by chemical production and transportation industries, which have seriously affected people's daily life. GIS has superior spatial analysis and data management functions. This paper builds a diffusion model of urban atmospheric pollutant VOCs based on GIS technology, provides intuitive, scientific and effective data for assisting atmospheric pollution emergency work, and studies and analyzes the atmospheric pollution diffusion simulation in Central Urban Area of Changsha City. The results show that GIS has a wide range of applications in the atmosphere, including data preprocessing, secondary development of models, final data processing, and display output of computing results. Map Objects is introduced to confirm the feasibility and necessity of integrating atmospheric pollution diffusion research with GIS. The study on VOCS diffusion model of atmospheric pollutants in central urban area based on GIS finds that the atmospheric pollution characteristics and pollution sources distribution of VOCs in the central urban area of Changsha City are closely related to the environment of the built-up area.