A method for repairing an inorganic thermal insulation mortar system, which relates to the field of thermal insulation of building walls, comprising step 1, setting a slot that runs through the inorganic thermal insulation mortar system, and the bottom of the slot is the base wall; step 2, removing the surface of the inorganic thermal insulation mortar system Respectively expand and extend to the top and bottom of the slot to form an expanded surface, extend the expanded surface to the plaster layer, and expose the mesh cloth, that is, the expanded mesh cloth; Step 3, install water-proof in the slot strip, and bond the inner side of the water-separating strip to the bottom of the groove; step 4, lap the outer side of the water-separating strip with the expanded grid cloth, and apply the plastering glue to form a protective layer; step 5, apply the inorganic The surface of the thermal insulation mortar system shall be repaired according to the original finishing requirements. The present invention relates to a method for repairing an inorganic thermal insulation mortar system. Grooving can effectively release the stress of the inorganic thermal insulation mortar system; it can effectively block the spread of water on the wall, quickly reduce the water seepage area, and protect the inorganic thermal insulation mortar system.