Based on quartz fiber as gain medium,the power coupling wave equation of multi-wavelength bidirectional pump Raman fiber amplifier is solved by Runge-Kutta method and shooting method,and the gain bandwidth,average gain,gain flatness and the distribution of pump light and signal light along the fiber are obtained.Then the particle swarm optimization algorithm is used to optimize the two-way system with the same number of pumping light and different arrangement.Three kinds of structures with better performance are selected from 14 kinds of bidirectional pump structures,and then the parameters are optimized.Finally,the bidirectional pump structure BBFF with the best performance is obtained.The results show that when there are only four pumping lights,the bidirectional multi-pump structure BBFF has the optimal average gain and gain flatness,and the bidirectional pump structure with switching gain of 23.1665 dB and gain flatness of 0.794 dB is obtained.