The prevention and control of environmental risks, especially incidental environmental risks, are essential for building an eco-environmental safety system. Risk assessment is an important premise and foundation for effective environmental risk management that can provide management priorities. Although many scholars have made substantial contributions to risk assessment of environmental incidents at the enterprise and regional scales, there is a lack of systematic assessment at the national scale. In this paper, we assessed the spatially resolved environmental incident risks at a resolution of 1 km × 1 km in China at the national scale based on risk field and vulnerability theories. Our results show that the proportion of high-risk areas account for 0.5% of mainland China, and the relatively high-risk areas account for 1.2%. The relatively high or above-risk levels are primarily distributed throughout the Yangtze River Delta Region, Pearl River Delta Region, Bohai Rim Region, and Chengdu-Chongqing Region. Spatially resolved maps enable us to understand the spatial characteristics and identify the hot spots of environmental incident risks, which can provide scientific references for macro policymaking relating to environmental risk management. Adjustments to industrial layout and structure are recommended to reduce the risk levels of incurring environmental incidents in China.