The sustainability and risk resilience of the insurance fund are crucial to the functioning of the social health insurance system. The outbreak of COVID-19 in early 2020 has stimulated discussion on the capacity of China's social health insurance to deal with major public health emergencies and on the construction of relevant systems. This paper constructs an actuarial model of health insurance fund for urban workers and for urban and rural residents, explores the impact of the COVID-19 patient treatment costs on the sustainability of Wuhan's health insurance fund, and selects five other provincial capital cities with different ranges of per capita disposable incomes to simulate and analyze the impact of COVID-19 on their health insurance funds. The results show that the impact of the epidemic on the sustainability of the health insurance fund is mainly concentrated in the short term, specifically, sustainability of the social health insurance fund for urban workers will not be significantly affected, but the resilience of the health insurance scheme for urban and rural residents is weak. Without taking into account the possible deferred health expenditures, the urban and rural residents' scheme in Wuhan and the other three cities in the simulation analysis will have current deficits in 2020 due to COVID-19 although not big enough to affect the fund's long-term balance. In addition, the government's financial burden of medical expenses is heavy, with the overall share of costs ranging from 33.19% to 37.07%. In order to improve the resilience and sustainability of China's health insurance system, it is suggested to promote the provincial-level pooling of health insurance, establish central adjustment fund and emergency reserve fund for health insurance, and improve collaborative governance in public health.