A reshaping Brillouin amplifier is combined with the main Brillouin amplifier in the conventional stimulated Brillouin scattering (SBS) phase conjugation mirror (PCM), which can control the SBS pulse shape, the main amplifier controls the pulse shape roughly, while the reshaping amplifier can control it finely. Effect of pump on pulse shape is studied, and the dependence of the pulse shape on the distance between the two amplifiers is achieved at various pump intensities. Results show that the pump intensity determines the amplifying efficiency of the seed, and that it is an important parameter to control the pulse shape.