The GB/T 31586.2-2015 standard specifies the evaluation and acceptance criteria for coating adhesion/cohesion (failure strength) in the anti-corrosion protection of steel structures by protective coatings system, mainly involving two methods: cross-cut test and cross-cut test. The cross-cut test evaluates the adhesion and cohesion of coatings by drawing a right-angled grid pattern on the coating surface, and the cross-cut test by making an "X" -shaped incision and penetrating to the substrate. The standard describes the test method, equipment requirements, inspection area, sampling scheme and acceptance criteria in detail, which are applicable to the quality control and acceptance of steel structure coatings. This standard is equivalent to the international standard ISO 16276-2:2007, which has international versatility and provides a scientific basis for the performance evaluation of steel structure protective coatings