Aimed at the problem that the existing literature to analysis influence of structure parameters on the interior ballistic performance is based on the single variable method on no consideration of the coupling relationship between the structure parameters, an integrated simulation model from the opposite design of internal ballistic equation to the positive calculation of interior ballistic equations is established, the coupling relationship between the structure parameters is considered, the modification method of interior ballistic design equation is put forward, and the variation law of interior ballistic performance based on the two dimensions of space dimension and time is analyzed. The simulation results indicate that design equations are derived in simplification causing the truncation errors and magnifying ideal throat area, and with the increase of low pressure chamber diameter the amplification becomes obviously. In designing a particular cylinder velocity and working pressure of high pressure chamber, the smaller the initial diameter and the height of the lower pressure chamber is, and the smaller the throat area is, and the greater the impact load of the missile is, and the shorter the movement time of the missile is. Choosing a reasonable size of the lowpressure chamber can make the maximum pressure of the low pressure chamber and the maximum acceleration missile arbitrarily adjustable.