Rapid three-dimensional model reconstruction method for closed space

The invention discloses a closed space three-dimensional model reconstruction method, and provides a rapid real-time network construction method for dark closed environments such as tunnels and coal mines. The method comprises the steps of closed space handheld SLAM system data collection, closed space three-dimensional point cloud generation, collected point cloud preprocessing, rapid three-dimensional networking and model optimization, and comprises the steps of traversing each point, judging an existing cavity triangle, establishing a circumcircle for the found cavity triangle and then deleting the triangle. All triangles of which the vertexes comprise the auxiliary windows in the remaining polygons are deleted, so that automatic filling and repairing of the vulnerabilities are realized. The method comprises the following steps: collecting closed space point clouds, and then performing pre-integration by using an IMU to compensate the motion distortion of each point cloud; then the point cloud is preproces