Core contents of the standard: First, quality inspection system, establish a three-dimensional inspection system of "maintenance process compliance, maintenance project integrity, maintenance quality effectiveness", with a total of 68 inspection indicators, covering the entire elevator system; Second, hazard classification standard, divide safety hazards into three levels: general hazards (do not affect safe operation, rectification within 7 days), relatively large hazards (affect local safety performance, rectification within 3 days, suspend relevant functions), major hazards (seriously endanger safety, stop use immediately for rectification); Third, inspection method specification, clarify the operation process and judgment standards of visual inspection, function test, instrument detection, and data verification to ensure that the inspection results are repeatable and traceable; Fourth, quality evaluation rules, formulate maintenance quality scoring standards, divided into three grades: excellent, qualified and unqualified. The evaluation results can be used as the basis for property to select maintenance units and supervision departments to carry out hierarchical supervision; Fifth, closed-loop management requirements, clarify the whole process requirements of hidden danger rectification, review and cancellation, to realize the closed-loop management of "inspection-classification-rectification-review".