A coupled level set and Particle-In-Cell method is presented to treat the penetration problems. The coupled method has the advantages of level set method and Particle-In-Cell method, and the basic idea is that the important computation region such as the large deformation region where more particles are added for calculation, while the continuous transport method is used in the other regions. The steel projectile penetration into concert target is simulated by using the above-mentioned coupled method. The numerical results reveal that the adopted coupled method can effectively track the deformation in the process of penetration and also insure efficiency and precision.