Abstract: A better understanding of the behavior of the debris cloud model under the hypervelocity impact is important for designing the shield structure of spacecraft. In this paper, a numerical simulation method is proposed to study the inner and outer boundary model of the debris cloud. According to its origin, the debris cloud is classified into the target cloud and the projectile cloud. The inner and outer boundaries of the cloud shape are determined according to the distribution characteristics of each cloud. The curves of Bernoulli’s lemniscates are modified into a combination of lemniscates and circles. It is shown that the modified curves are more appropriate to fit the actual debris shape than the lemniscates.