In the parachute ejection process, there is a significant difference between the estimated ejection speed and the actual ejection test results. An energy consumption issue can not be ingored in the ejection process, and it is difficult to accurately describe the ejection consunmption mechanism of the ejection process in current research. Firstly, the counterweight ejection simulation is performed using the catapult. Then, a spring-damping dynamic model of the catapult combination is established. Using the simulation results of the ballistic counterweight and the data from the parachute test as inputs, the key parameters of the spring damping model are solved through data fitting. Finally, completed the dynamics simulation of parachute ejection from the capsule and verified under another test condition. The investigation revealed that the spring damping model can accurately describe the parachute ejection process from the capsule. When the damping coefficient remains constant, the greater the stiffness coefficient of spring, the less energy the parachute pack will ultimately dissipate. When the stiffness coefficient of spring remains constant, the greater damping coefficient, the more energy the parachute pack will ultimately dissipate. The higher the proportion of rigid mass in the ejection assembly, the less energy consumption. The research results can provide some reference for parachute package design and energy dissipation analysis of parachute ejection process from the capsule.