Abstract: Using the nuclear bomb explosion to directly destroy the asteroid or to change its orbit so as to avoid its impact on earth is one of the main methods in the defense against near earth orbit asteroids. Based on the concept of the hypervelocity asteroid interception vehicle (HAIV) developed by Iowa State University, this paper proposes a scheme of using a long rod impactor instead of the original impactor. The crater forming process of the long rod impactor impacting the asteroid is simulated by using the Euler type hydrocode NTS developed by us. The deflections and damages of the nuclear device exploded in various depths are simulated by adding an energy source into the simulation. The results show that by using the long rod impactor with a reasonable impact velocity, the nuclear device can be guided into a deeper place and exploded in the asteroid, thus the nuclear explosion energy can be more efficiently used, and the ability to deflect or destroy the asteroid can be enhanced.