Objective: To explore the establishment of a dynamic funding mechanism for urban and rural residents’ medical in- surance with a fair burden of contributions and balanced responsibilities. Methods: It establishes an actuarial model based on the fi- nancing mechanism of the fixed ratio of disposable income to measure the sustainability of the operation of the basic medical insur- ance system for urban and rural resident fund. Results: The financing mechanism based on the individual contribution rate of 1.07% and the government subsidy rate of 2.14% can ensure the stable operation of the residents’ medical insurance fund in the medium term, and the accumulated balance rate is within a reasonable range. In 2035, the accumulated balance of the residents’ medical in- surance fund can maintain the expenditure of 17.60 months, and it can maintain the expenditure of 8.4 months under the pressure test. At the same time, the increase of individual contributions is within a reasonable range. The financing mechanism of fixed-ratio funding mechanisms is operability. Conclusion: It is suggested to establish a proportional financing mechanism under the provincial overall planning and implement gradual reform of residents’ contribution rate.