For the normal single-mode optical-fiber,the frequency shift and optical power of Brillouin scattering light are the functions of the temperature and strain. So,the temperature and strain of the optical-fiber can be obtained together,when Brillouin frequency shift and the optical power are able to be detected simultaneously. Brillouin optical time domain reflectometer with coherent detecting is suitable for long-distance distributed sensing,but there exist two critical problems. One is the polarization relative detecting signal;the other is how to demodulate the wideband photoelectric signal. The orthogonal polarization diversity reception and real-time wavelet transform are adopted to deal with these problems,in order to get the frequency and power of the scattering light at the same time. The experimental procedures and results are presented in the text. A laboratorial system of 25 km distributed Brillouin optical time domain reflectometer is achieved for two-parameter sensing.