Urban expansion is the spreading process of urban construction land overcoming ecological resistance. In this paper, we introduced relative resistance factors on different source levels in the minimum cumulative resistance model (MCR), and considered the inherent constraints and epitaxial ecological resistance on town expansion. Then, we constructed an improved minimal cumulative resistance (IMCR) for urban expansion simulation. The ecological resistance surface of Yuzhong county was formed to simulate the spatial distribution and boundary of town expansion to 2030. The results show: (1) the spatial difference of comprehensive ecological resistance in Yuzhong County is significant, which is decreasing from south to north. The urban expansion is affected by the ecological environment. In addition, the ecological constraints of urban expansion are higher in the areas with better ecological quality. (2) When the ecological constraints are high, the simulated area of urban expansion is smaller than the planned area. On the contrary, when the ecological constraints are low, the simulated area of urban expansion is larger than the planned area. The urban expansion boundary under the planning scenario is relatively straight, simple and rigid, and the town boundary under the ecological constraint scenario is a curve, complex and irregular. (3) The simulation results based on the IMCR model are more in line with reality and reflect the requirements of ecological protection. From the perspective of urban expansion scale and intensity control, the simulation results are more in line with actual needs and reflect the direction of policy regulation.