Herein, using a fast Brillouin optical time-domain reflectometry system with a wideband receiver and distributed Raman amplification, a long-distance distributed Brillouin sensing is realized. We study the performance difference and nonlinear phenomena observed in the system before and after Raman amplification, and also jointly optimize the Raman pump and launched pulse powers. Our experiments achieve a sensing distance of around 100 km with a spatial resolution of 50 m and accuracy of 1.2 ℃ at a sensing position of 50 km. In comparison to the system without Raman amplification, the sensing distance is increased by approximately 50 km and measurement can be completed in approximately 10 s only.