Abstract: In order to achieve the goal of "Healthy China", China's basic medical insurance system has continuously improved the level of medical insurance and expanded its coverage. The unified management of basic medical insurance for urban and rural residents is a significant improvement in the medical insurance rights and benefits of the people covered by the former new rural cooperative medical system. Based on the quasi-experiment of the unified management of medical insurance for urban and rural residents and the time difference of its implementation in different administrative regions, this paper examines the impact of the expansion of medical insurance coverage and the increase in reimbursement rate on the medical treatment behavior and consumption of rural households through a multi-time difference-in-difference model. On average, the unified management of medical insurance for urban and rural residents has increased the medical expenditure of rural households by 11.6% and reduced the proportion of family members visiting primary medical institutions by 1.5%. Over time, the stimulating effect of the policy of unified management on medical expenditure has decreased, but the impact on the medical treatment choices increases continuously. The results of heterogeneity analysis suggest that the groups that are more affected by the policy of unified management of medical insurance for urban and rural residents are the households without chronic diseases and the low-income households with purely agricultural employment. The former may be due to the insufficient release of medical needs of rural households except for those with members suffering from chronic diseases, while the latter may be due to the greater flexibility of consumption price and income for consumption of low-income households. Further study shows that the policy of unified management has no significant effect on the original group that is covered by urban residents' basic medical insurance.