In Brillouin optical time domain reflectometer,the detected spontaneous Brillouin scattering light is very weak,and the Brillouin frequency shift is only about 11 GHz. The coherent detect is a good method,but the detected signal is a wideband amplitude-modulated signal,which is hard to demodulate. The real-time Morlet wavelet transform is adopted to overcome this problem. The experimental procedures and results are presented in the text. A laboratorial system of 25 km distributed Brillouin optical time domain refractor is achieved,with the stress resolution of 40 με,the spatial resolution of 5m and the system response time of 1 minute.