Volume and pre-charge pressure are the key parameters of the gas-filled accumulator, which have a great influence on its dynamic performance (the output performance of pressure and flow under working conditions).To provide a reference for the reasonable calculation and selection of accumulator parameters. , this paper takes the calculation and selection of a certain type of aircraft rudder surface emergency gas accumulator as an example, based on the hydraulic component library in the Hypneu simulation software, combined with the main design parameters of this type of aircraft hydraulic system and the working principle of the emergency accumulator, to establish an accumulator The simulation model of the actuation of the accumulator is established, and the test points are set in Hypneu to record the simulation curve, and the influence of the key parameters of the gas-filled accumulator on its dynamic performance is explored by analyzing the simulation curve. In addition, this paper combines theoretical calculation and simulation analysis to propose a set of Accumulator parameter selection method, and the selection method is verified by experiments. The results show that: the greater the pre-charge pressure of the accumulator, the smaller the effective volume output by the initial accumulator, and the reduction of the pre-charge pressure increases the effective volume at the same time. The output pressure of the accumulator will be reduced, the experimental results are close to the simulation results, and the accumulator selected by this method can meet the actuation requirements.