Abstract: The multiscale analysis method of explosive load based on the substructure of explosion source provides an efficient solution for numerical calculation of explosions in complex situations and large-scale sites. Although this method has a clear theory and high computational efficiency, it involves the comparison and rewriting of a large number of spatial node data, and there may be some problems in the application of finite element software. In this paper, the basic theory of the method was briefly introduced, and the application technology of the method in simulation calculation was studied. A comparative analysis of two examples of single-explosive source and multiple-explosive source was carried out. The research results show that the explosive load multiscale analysis method could be applied to the dynamic response calculation of large-scale engineering sites under the action of large-equivalent explosion loads, and the calculation efficiency was significantly better than that of the explosive-medium-target overall calculation model. Avoiding repeated modeling and fluid-structure interaction analysis, the calculated standardized explosion load can be loaded to any position of the medium, significantly improving calculation efficiency. Programs based on Python can efficiently and accurately compare and rewrite spatial node coordinates and data, greatly improving preprocessing efficiency.