Abstract: The evaluation of land space development suitability is the basis for scientific development and rational layout of land space while functional zoning providing scientific evidence for the optimization of land space development. They are important for the sustainable development of social economy. This paper selects Yanchuan County, an area with a high incidence of geological hazards, as a research example, and evaluates the suitability of land development on a grid scale of 30×30 m in 2018. Based on the evaluation results, the functional zone of Yanchuan County is carried out by using the three-dimensional magic method. The results show that due to the constraints of geological disasters and other factors, the suitability of land space development in this area has an agglomeration effect. The area of high suitability, moderate suitability and low suitability accounted for 27.16%, 48.55%, 24.29 respectively. The area with the most restrictive land development is consistent with the high-prone area of geological hazards. The areas with the most development are Dayu street, North of Yongping Town and the partial of Wen Anyi Town. The areas with the greatest potential for future development are mainly located in areas with rich mineral resources such as Wen Anyi Town and Yongping Town. The urban construction leading area, the agricultural development leading area and the ecological protection leading area accounted for 7.22%, 48.38% and 44.40%, respectively. The research provides a scientific basis for the formulation and optimization of future land and space planning in Yanchuan County.