Objective: To analyze the current situation of the fund income and expenditure of China"s basic medical insurance and its constituent risks based on the perspective of sustainability, and to make a prediction and analysis of the development trend of China"s basic medical insurance income, expenditure and balance, with a view to providing a scientific reference basis for the formulation of China"s basic medical insurance policy in the future Tenth Five-Year Plan period. Methods: The income and expenditure data of China"s basic medical insurance and its constituent insurance categories from 2009 to 2022 are selected as the forecast indicators, and a gray GM (1,1) forecast model is constructed to forecast the fund income and expenditure scale and balance of China"s basic medical insurance and its constituent insurance categories. Results: From 2023 to 2030, the scale of China"s basic medical insurance fund and its constituent risks is expanding, but the growth rate of current fund balance is decreasing, and there is a risk of forward deficit in the medical insurance system, and the expansion of the scale of the medical insurance fund has slowed down during the Tenth Five-Year Plan period. Conclusion: The operation of the MBF is stable, but there are potential structural risks. In the future, we should further optimize the operation mechanism of the medical insurance fund, adhere to the function of the medical insurance system in providing for people"s livelihood, eliminate the regional and structural differences in the level of protection of the insured groups, and improve the service level to ensure the sustainable development of the system.