This standard is formulated under the jurisdiction of the National Technical Committee for Elevator Standardization of China. It is applicable to the safety upgrading transformation and safety evaluation of in-service escalators and moving walks, covering in-service escalators in all scenarios such as commercial complexes, rail transit, airports and stations. The core contents of the standard include: first, establishing the general principles of safety upgrading of in-service escalators, establishing a safety risk classification and assessment system for in-service escalators in accordance with the principles of "risk classification, transformation as needed, safety first, economy and applicability", dividing them into three levels: major risk, relatively large risk and general risk according to the risk level, and clarifying the safety upgrading requirements and rectification time limits corresponding to different risk levels; second, refining the core safety protection upgrading requirements, formulating special upgrading requirements for handrail speed deviation monitoring, step missing monitoring, skirt panel anti-clamping device, anti-climbing device, non-operation reversal protection and emergency stop device in view of the common potential safety hazards of in-service escalators, and clarifying the minimum safety configuration standards for escalators with different service lives and use scenarios; third, improving the technical specifications for the transformation of old escalators, formulating special technical requirements for core component replacement, control system upgrading and safety device installation for old escalators with a service life of more than 15 years, and clarifying that the performance indicators and safety standards after transformation must meet the requirements of the current mandatory national standards; fourth, standardizing the safety evaluation method of in-service escalators, formulating the process, indicators and grading standards for safety risk assessment of in-service escalators, clarifying the acceptance inspection items, test methods and qualification judgment criteria after transformation, and incorporating the safety upgrading effect into the core content of regular inspection of escalators; fifth, refining the operation and maintenance and long-term management requirements, clarifying the special requirements for daily inspection, regular maintenance and regular inspection of in-service escalators, and formulating special specifications for encrypted maintenance frequency and strengthened component inspection for high-load operation escalators in rail transit and airports. The implementation of this standard has comprehensively standardized the safety upgrading and transformation market of in-service escalators and moving walks in China, effectively reduced the safety accident risk of old escalators, and also promoted the standardized development of China's escalator transformation technology and core components, providing Chinese standards and Chinese solutions for the global safety upgrading of old escalators.