Abstract: Dynamic deformation of virtual terrain is an important research content to enhance the dynamic adaptability of virtual geographic environment, which can support disaster simulation, combat simulation and so on, and also an important support to study human-environment interaction. Taking the dynamic generation of crater as an example, starting from explosion physical force and geometric fitting of crater shape, the construction method of virtual terrain deformation model is explored, and the calculation method of crater shape model is proposed, which coupled with geological characteristics. Compared with the existing results, the method is coupled with a variety of projectile parameters at the same time, which is convenient for the introduction of geological characteristics parameters, and can effectively calculate the explosion effect of different projectiles in different geological environments under different incident angles. At the same time, the existing method of crater region texture generation is improved. The new method considers the problem of texture map mixing in the case of multi-media composition of crater region. The verification results of unity show that the crater model can reflect the impact of different projectile incidence angle, explosive equivalent and geological characteristics. The deformation state of crater is similar to the actual situation, and the map of crater area can reflect the impact of different geological texture. The research results can provide support for the simulation of the dynamic change process of the crater, which caused by the projectile touchdown explosion in the virtual battlefield environment.