The invention discloses a point cloud synthesis method based on constraint of a depth map. The method includes following steps: (1) designing a shooting scene, and arranging cameras by regarding a to-be-reconstructed target as the center; (2) calibrating the cameras: estimating internal and external parameters of the cameras by employing a calibration reference object or a scene self characteristic point; (3) obtaining scene sparse point clouds according to a multi-image stereoscopic vision characteristic matching relation; (4) deriving dense point clouds according to the sparse point clouds; (5) reconstructing an object surface by employing the dense point clouds; and (6) performing mapping according to the internal and external parameters of the cameras and a surface reconstruction model.