Background Background: Healthcare-seeking behavior is a key indicator of the efficiency and equity of a healthcare system and is crucial for achieving universal health coverage. Against the backdrop of China’s ongoing reforms to its healthcare security system and the integration of its social insurance system, identifying the factors influencing residents’ healthcare-seeking behavior is of great significance for accurately evaluating policy outcomes and optimizing resource allocation.Methods Using the Anderson model, we integrated data from the China Family Panel Studies (CFPS 2022, all ages, N = 8,610) and the China Health and Retirement Longitudinal Study (CHARLS 2020, middle-aged and elderly, N = 10,354). Binary logistic regression analyzed the interaction effects between insurance type (public, NRCMS, urban resident, urban employee, uninsured) and household financial risk (medical expenditure/household income: low < 0.1, medium 0.1–0.4, high ≥ 0.4), with robustness checks conducted using gender subgroups and complementary log-log models.Results The financial risk effect showed population heterogeneity: high-risk individuals in CFPS had a 7.60-fold increased probability of hospitalization, while high-risk individuals in CHARLS had a 2.19-fold increased probability of outpatient visits. Health insurance effects varied by system: In CFPS, urban employee medical insurance users had lower outpatient utilization than the uninsured (OR = 0.79, 0.62–0.99) but higher hospitalization (OR = 1.89, 1.15–3.09); in CHARLS, new rural cooperative medical scheme users had lower hospitalization than the uninsured (OR = 0.48, 0.23–1.00). Interaction effects were significant: In CHARLS, the combination of New Rural Cooperative Medical Scheme (NRCMS) and high financial risk increased inpatient care utilization (OR = 2.20, 1.00–4.86), while in CFPS, the combination of Urban Resident Medical Insurance (URMI) and high financial risk suppressed inpatient care utilization (OR = 0.14, 0.02–0.92). Women were more sensitive to financial risk, exhibiting a more pronounced demand-release effect from health insurance.Conclusion Health insurance and household financial risk exhibit synergistic effects on healthcare utilization, with effects varying by system, age, gender, and service type. Efforts are needed to enhance the actual coverage level of rural health insurance, establish dynamic financial risk intervention mechanisms, and guide urban employees toward rational healthcare utilization.