Abstract: Based on data from the 2017 China Household Financial Survey (CHFS), this study employs the Probit model to analyze the impact of household participation in multi-level medical security on household catastrophic health expenditure. The findings indicate that participation in multi-level medical security significantly reduces the risk of household catastrophic health expenditures, with participation in commercial medical insurance significantly reducing this risk. Compared with the participation of households from the central region and with high health capital, participation of households from eastern and western areas, with low health capital, has a higher probability of significantly reducing their households’ risk of incurring catastrophic health expenditures by enrolling in multi-level medical security. Compared with high-asset households, low-asset households significantly reduce their household’s risk of incurring catastrophic health expenditures by enrolling in multi-level medical security. Based on these findings, the study proposes that the risk of household catastrophic health expenditures should be further reduced primarily by enhancing the protective capacity of the different medical security programs under the multilevel medical security system.