To improve the precision of initial orbit of spacecraft in launching phase,to execute timely and accurate TT&C in early orbit phase,and to meet the need of the users,this paper puts forward an initial orbit determination method which regards measurement datum and precision of all kinds of redundant and backup equipments as the input parameters of the optimization model and determines the optimized orbit based on Particle Swarm Optimization(PSO) method.The result indicates that it is significant to improve the precision of initial orbit of spacecraft by using a number of measurement data and the precision of different redundant and backup equipments.This algorithm is proved to be accurate and effective,and can be used both in the initial orbit determination and in the spacecraft orbit optimization in operational phase.