The invention discloses a cardiac activity monitoring device and method. The cardiac activity monitoring method comprises the steps that 1, double hands are put on an electrode of a remote control unit for measurement; 2, after the remote control unit monitors the heart rate, an electrocardiogram acquisition module is started; 3, the remote control unit sends a wireless connection request to a smart television, and after wireless connection confirmation is received, the electrocardiogram acquisition module is controlled to send data; 4, the smart television receives the data sent by the electrocardiogram acquisition module, performs analysis and displays an analysis result. An electrocardiogram detection function in a home environment is achieved by using the smart television and the remote control unit, the electrode is arranged on the remote control unit to perform data acquisition, data transmission is performed through wireless communication between the remote control unit and the smart television, electrocardiogram display is performed on the smart television, operation is simple, refitting is performed by using the existing remote control unit and the smart television, the costs are reduced, and the cardiac activity monitoring device is small in size and convenient to use.