Polypropylene fibers are in the construction field, so that the whole building is in humid conditions, and it is easy to cause aging and corrosion in all aspects. Importantly, stones with high water absorption are prone to freeze-thaw. In order to ensure that the anti-crack fibers can be well dispersed in mortar, cement and concrete, the anti-crack fibers are also subjected to a special process to the surface before cutting. Because it mainly uses polypropylene as a raw material, it is also called polypropylene fiber. Anti-crack fibers act on mortar and cement concrete. With its unique tensile strength, dispersibility, melting point, acid and alkali resistance, etc., it can effectively prevent the generation and development of maintenance cracks in mortar and cement concrete. Thus, cracks are effectively prevented. The correct approach should be to lay an alkali-resistant fiberglass mesh woven from alkali-resistant fiberglass in a plastered mortar with good flexibility (compression ratio 3), close to the side of the surface layer. The flexible ultimate tensile deformation of plastered mortar should be greater than the sum of its own deformation f dry shrinkage deformation, chemical deformation, humidity deformation, temperature deformation) and base deformation under adverse conditions, so as to ensure the crack resistance requirements of the protective layer. If the exterior finish is a facing brick. Steel wire mesh can be added to cement anti-crack mortar. However, the wire diameter and L distance of the steel wire mesh should be determined by tests. The short side of the facing tile should be covered on at least two mesh L, and the steel mesh should be hot-dip galvanized steel mesh with good corrosion resistance (rust). External insulation systems should undergo large-scale system weather resistance tests to verify their crack resistance. In external insulation projects, the protective materials and finishing materials of the outer insulation material surface must withstand climate changes such as heat and cold, temperature and humidity, freeze-thaw for a long time. Therefore, in order to verify the stability and service life of the outer insulation system... the method is to conduct a weather resistance test. For example, the application cracking phenomenon of extruded poly board insulation is common. Research on system material properties and material matching should be added to this type of external insulation system.