A reshaping Brillouin amplifier is suggested to combine with the main amplifier in the system of the stimulated Brillouin scattering (SBS) phase conjugate mirror (PCM). In this novel scheme, the main amplifier can coarsely tune the output pulse shapes, while the reshaping amplifier is to finely control the output pulse shapes. Effects of encounter time on pulse shapes are theoretically and experimentally researched, and pulse shapes versus the distance between the two amplifiers are achieved with various encounter time. Results show that the encounter time decides the general pulse shape and is an important parameter to control the pulse shape. The longer the encounter time, the wider the control range, and the lower the efficiency of the system.