The research on the differences of impulse environment between the single-hull and the double-hull submarine has significant meaning to the structural design of the single-hull submarine.A model of a single-hull submarine is derived from a double-hull submarine by sharing the shell equally.The software ABAQUS is used to simulate the impulse environment of the submarine underwater explosion.The time history data of acceleration are transformed into an impact spectrum to get average spectral velocities.The impact responses of typical parts and along the length of submarine are compared between the single-hull and the double-hull submarine.The results indicate that the acceleration response values and the impact spectral value of the double-hull submarine are lower than that of the single-hull submarine and the responses of the double-hull submarine are more integrity.