An improved Simulated Annealing(ISA) method for fast optimizing distributed multi-pump Raman amplifier(DMRA) was presented.A simple algorithm for counter-pumped DMRA was derived through reasonable approximations.The proposed ISA can effectively solve the multimodal optimization including the global and local optima in the DMRA.Optimization results show that,under the conditions of the ON-OFF gain of 10 dB,the relative gain flatness of <0.12 and the fiber haul of 80 km,amplifier bandwidths at larger 80 nm have been achieved with 4,5 and 6 pumps by using the optimization of the ISA.Comparing with other existing methods,the ISA method can attain a required low gain ripples and larger bandwidth with less pumps.