To comprehensively meet the test requirements for the common mode rejection ratio(CMRR)across different ECG-particular standards,this paper presents the design of an ECG CMRR automatic test system.The hardware component primarily consists of a test signal generation module,an automatic control network(which includes a resistance-capacitance network control module and a polarization voltage control module),and a noise level switching module.The software portion enables automatic control and user interaction.Experimental results indicate that the system is stable,reliable,and highly automated,capable of satisfying the test requirements of various ECG-particular standards,thus demonstrating a promising application prospect.