Abstract: For the problem of huge workload, long time and high computer configuration in calculating reverberation chamber(RC) electromagnetic(EM) field distribution, superposition incidence plane waves advanced in one-dimension, which are produced by a set of equivalent sources distributed randomly on the sphere under some restriction, are used to simulate the reflection EM waves produced by the stirrers in RC. Based on the former model, the finite-difference time-domain(FDTD) method is adopted to analyze the RC field distribution, and the number of superposition incidence plane waves required by different field uniformity is optimized. The results show that the method adopted in this paper not only shorten the computation time of designing RC effectively, but also lead to the optimized position and number of equivalent sources to meet the predetermined field uniformity purposefully. It makes the whole simulation intensification.