By combining theoretical derivation and experimental verification, research was conducted on how optical parameters affected the coherence efficiency of wind light detection and ranging (LiDAR). According to the superposition principle of optical fields, the influence of local oscillator waist and fiber coupler diameter and optical aberrations on coherent efficiency was discussed. Experiment of atmospheric turbulence effect was conducted, and the system signal-to-noise ratio with different optical parameters was measured under typical weather conditions. The consequence indicate that if the pupil aperture and F number are 100 mm and 2, the optimal beam waist and receive fiber diameter are 3.3 μm and 9 μm, and root mean square of the optical wavefront aberration is less than 0.06λ. Under strong turbulence, when the visibility is less than 5 km, the radar detection distance decreases by 60%. It has special significance for optimizing optical parameters to promote the study.、<英文关键词>laser technique; coherent efficiency; optical parameters; simulation and experiment