Abstract: The single-edge technique measuring Doppler shift of Rayleigh-scattering and Mie-scattering simultaneously is presented. The method is used to detect atmospheric wind velocity at low altitude（<12 km）. The error of the measurement caused by the atmospheric back-scattering ratio Rb can not be ignored. The measurement sensitivity and results are analyzed. The calibrated curve of wind velocity measurement is calculated under different value of Rb. The results show that the sensitivity tends to increase along with the increase of Rb and the error of measurement increases along with the deviation of Rb. At the same time, the measuremental error tends to increase with the augment of the radial wind velocity under the same deviation of Rb.