Objective:Efficiency is a key factor in the sustainable operation of the medical insurance system.By measuring the current efficiency of the urban employee basic medical insurance system in 31 provinces in China from 2020 to 2021,it discovers possible problems,and provides reference suggestions for improving the efficiency of the system.Methods:Using the super efficiency SBM model based on unexpected output and the Malmquist index to measure the static and dynamic efficiency of employee medical in-surance in 31 provinces in China,and using Tobit regression analysis to analyze its influencing factors.Results:The overall compre-hensive efficiency of the national employee medical insurance operation is 0.826 in 2020 and 0.827 in 2021 respectively.The efficien-cy of employee medical insurance operation in the eastern region is significantly higher than that in the central and westem regions.Over 60％of provinces have inefficient operation of employee medical insurance.The overall total factor productivity of employee medical insurance operation is showing a downward trend,and the decline in technological progress is the main limiting factor.The level of economic development has a significant promotion effect on the efficiency of employee medical insurance operation,and the degree of population aging has a significant inhibitory effect on it.Conclusion:The efficiency of employee medical insurance opera-tion in China still needs to be improved,and there is a significant efficiency gap among different regions.Therefore,investment and attention should be increased in the central and western regions to bridge regional gaps and promote the equity development of medi-cal insurance.Therefore,the reform efforts should be continuously intensified to achieve technological progress.In addition,attention should also be paid to the driving role of economic development in the efficiency of employee medical insurance operation and the for-mulation of positive policies on population aging.