The error of measuring Brillouin frequency shift based on brim detecting technology has great influence on the measurement precision of sea surface temperature. According to the measurement principle of brim detecting technology and the relation between Brillouin shift and sea surface temperature, a theoretical model which monitors sea surface temperature by detecting Brillouin scattering frequency shift based on brim detecting technology is established. The effect of brim detecting technology on the Sea surface temperature measurement accuracy is analyzed. The results show that the maximal error of measuring Brillouin frequency shift is approximately 0.33 MHz while Brillouin frequency shift is distributed from 7.2～7.9 GHz, and the measurement precision of sea surface temperature is 0.010 5 ℃. This study has good instruction significance to the design of sea surface temperature monitoring system.