A Raman fiber amplifier with multi pum p and GeO2doped microstructure fiber is designed to fulfil the requirements of 6G transmission system for optical communication network which can solve the pro blems of narrow band width,low output gain and uneven output gain of Raman fiber amplifier suitable for 6G system.In theory,using the fourth-order Runge-Kutta method is to solve the classical Raman coupled wave differential equations; in the structure,two pairs of pump beams with the same wavelength are combined to r educe the number of pumps and simplify the structure.At the same time,the method of cascading two sections of microstructured fiber is used to realize the signa l gain amplification before and after compensation at the output end of the Rama n amplifier.Finally,the average gain of the amplifier is up to 35.72dB in the b andwidth of 100nm,and the gain fluctuation is less than±0.43dB.