High repetition rate ultra-short optical pulse train generated by means of four-wave mixing(FWM) in fiber to compress dual-frequency beat signals has attracted considerable attention.However,the launched power into the fiber is limited by the threshold of stimulated Brillouin scattering(SBS) of the fiber,which has a great impact on the performance of the output pulse train.In this paper,we use a nonlinear fiber with high SBS threshold to compress dual-frequency beat signals by the FWM in the fiber.A 100 GHz pulse train is achieved experimentally and the output waveform impacted by the input power is analyzed.