Abstract: According to gas-debris clouds interaction process,initial model of secondary debris is built.The gas-debris clouds interaction process is analyzed based on gas-solid two phase flow theory.The computational model of gas-debris clouds interaction is build.The effects of projectile diameter,impact velocity and gas pressure was investigated.The result shows that the velocities of tip of debris clouds and the velocities of the extension of the debris cloud increase with an increase in projectile diameter,Shock-wave strength increases with an increase in projectile diameter.The acceleration of debris clouds deceleration increases with an increase in impact velocity and gas pressure.The shock wave strength increases with an increase in impact velocity and gas pressure.Attenuation velocity of shock wave increases with an increase in impact velocity and gas pressure.