Balanced receiver technique for signal detection in coherent lidar is analyzed.Mathematical modeling and signal-to-noise ratio of the balanced detection process is deduced.A numerical simulated system is established.For the same input signal，when the beam-splitter coefficient of balanced coherent detection is between 0.293 and 0.707,the signal-to-noise ratio of balanced coherent detection is higher than that of single detector coherent detection.And also direction of the wind can be obtained using the balanced detection technique，and experiment results are consisted well with simulation results.