Abstract: In order to study the impact resistance and compression resistance of mine permanent closed seal, and improve the mine resistance to disasters under complex conditions, this paper uses computer simulation method to carry out numerical simulation, establishes a composite seal model, and designs a series of computer simulation experiments to explore the deformation, stress and damage distribution of closed seal caused by explosion.The results show that according to the damage of the closed seal caused by explosion pressure, the damage of the inner seal can be divided into three stages.By comparing the mechanical properties and damage of the closed seal constructed by brick seal and C40 concrete seal under explosion load, it is found that the damage development rate of brick seal is significantly higher than that of C40 concrete seal, the explosion pressure of brick seal is significantly lower than that of C40 concrete seal, and the compression and deformation resistance of C40 concrete seal is significantly better than that of brick seal.Under the combined action of mine pressure and explosion load, the stability of C40 concrete seal presents different states, that is, the prestressed structure formed by lower mine pressure can gain little protection effect of the seal, while the higher mine pressure will aggravate the damage of the seal, and then lose the protective effect, which depends on the explosion damage stage of the seal.