Abstract: The process of escape and sucedent emergency separation of spacecraft modules when spacecraft rising besides aerosphere is a complex process of multi-body relative motion. The mathematic models of relative trajectory motion and attitude motion for that process, including dynamic, kinematic and geometric equations, are constructed. The combinatorial objects are defined, the relation between subject and object is emphasized, and the flight phase according to practical situation is partitioned. On the base of mathematic model, body definition and phase partition, a large-scale software to analyze and simulate is established. Some result samples of typical condition are given.