The development of a controllable parafoil system provides the prospects for precise，undamagea recovery of large delicate payloads and recovery return systems intended for reuse. In this paper a six-degree-of-freedom flight dynamics model for such a system is presented and the simulation program is developed to aid the study of system performance such as glide and dynamic stability etc. As an example，the glide and dynamic stability performance of 40 (sqm) are a parafoil system has been discussed and some satisfactory results were obtained.