Abstract: In order to investigate the law of surrounding rock stability for unloading coal-rock mass under different loads, the numerical simulation was carried out to analyze impact properties of unloading coal-rock mass when subjected to static load, impact dynamic load and superposition of static-dynamic load. The results showed that the influence of impact loading on the impact failure of unloading coal-rock was mainly the cycle disturbance of shock wave, the distribution effect not only caused spalling failure in coal seams of tunnel sides, but also led to splitting failure in top strata at large range. The influence of loading rate on the impact characteristics of unloading coal-rock mass was significant, the obvious difference included the peak of failure load, the failure regions, and the failure types, etc. The influence of static and dynamic load coupling was larger than that of single one on impact properties of unloading coal-rock mass.