Abstract: In order to study the measure error of detecting Brillouin scattering based on edge detecting technology,the measure error formula of detecting the Brillouin scattering signal was educed after analyzing the underwater channels.At the same time,the Brillouin scattering signal was estimated based on the formula.The frequency drift of Brillouin scattering was simulated under the condition of different depth and the different water quality parameters.Under good quality water,the measure error of the Brillouin scattering frequency drift was less than 5MHz at 120m underwater.Based on the above results,a final conclusion is concluded that higher signal-to-noise ratio and smaller measure error could be acquired based on the edge detecting technology.