Abstract: The calculation accuracy and execution time which directly impact on the performance of a fire control system, are contradict each other. Therefore, it is significant to shorten the time of resolving algorithm of ballistic equations without decrease the precision. The parallel method of ballistic based on the improved particle swarm optimization algorithm is able to make good use of a multi-core computer by adopting concurrent computation. Firstly, the process of resolving ballistic equations was translated into a process of optimization by introducing the particle swarm optimization method. In order to improve the rate of convergence, the correction angle obtained through Zhou's iterative correction formula was used to guide the update of particles. Then the parallel method was gained through distributing each particle to threads in parallel domain. Finally, the results of practical calculation examples show this method can efficiently improve the rate of convergence and reduce the average time to one fifth.