Abstract: The paper analyzed current situation of safety monitoring and control systems of coal mine, established an assessment model for grading verdict of hazard level of operation areas based on safety monitoring, and designed an environmental safety assessment system of operation area in mine. It introduced design idea, structure principle and main functions of the assessment system in details. The assessment system can make dynamic analysis and comprehensive evaluation for change of environment parameters of main operation areas in mine underground, and give hazard level of the operation areas with different colours, which provides reference to insure environment safety for workers in mine underground. The assessment system can not only run independently, but also run as a function section of safety monitoring and control system.