The parachute deployment process is the key stage to ensure the safety and reliability of parachute-payload system. The deployment system is a complex non-linear dynamic system involved in variable quality and freedoms of three-dimensional multi-body objects. Some key problems of flexible parachute deployment dynamic simulation technology are discussed. The simulation methods are introduced at first and the characteristics of each method are analyzed by actual numerical examples. Then, the relationship between main factors of deployment dynamic model is constructed and the influence of wind velocity on deployment process is analyzed. Moreover, some tension model and their features are given, and the application ranges of these tension models are pointed out. Finally, several problems of parachute deployment simulation are proposed, such as the way to decrease the error and some ones that should be taken into account in the future.