Overhaul is mainly to improve mine roadway and transportation roadway, and the safety technical measures for overhaul should be compiled and approved by the mine manager. When repairing or expanding the roadway section, the support near the work site should be strengthened first, then the support at the work site should be removed and temporary support should be done well. The number of supports to be removed from the work site at a time shall be determined according to specific conditions, and dense supports shall be removed. No more than two at a time. In order to replace the support at the position of soft roof, or repair the intersection of roadway and serious roof caving area, tie rods must be added between the supports or temporary supports must be erected. When cleaning pumice, tools must be operated in a safe place. When maintaining the inclined shaft, the vehicle should stop driving, and set up warnings and obvious signs. When replacing the single-headed roadway support, no one may be inside.

When maintaining the shaft, the construction organization design must be compiled. Must work on a solid platform, the platform should have protective facilities and contact signals, and there should be reliable communication between the working platform and the middle drift. Operators should fasten their seat belts. Before operation, pumice on the middle horsehead gate and well frame should be cleaned up, and the middle horsehead gate should be supervised by special personnel.