A depth perception method combining omnidirectional images and encoding structured light was proposed. First, a new structured light pattern was presented by using monochromatic light. The primitive of the pattern consists of four-direction sand clock-like (FDSC) image. FDSC can provide more robust and accurate position compared with conventional pattern primitive. Second, on the basis of multiple reference planes, a calibration method of projector was proposed to significantly simplify projector calibration in the constructed omnidirectional imaging system. Third, a depth point cloud matching algorithm based on the principle of prior constraint iterative closest point under mobile condition was proposed to avoid the effect of occlusion. The experimental results demonstrated that the proposed method can acquire omnidirectional depth information about large-scale scenes. The error analysis of 16 groups of depth data reported a maximum measuring error of 0.53 mm and an average measuring error of 0.25 mm.