According to the requirements of each module's hardware function, the DC-DC conversion circuit, frequency conditioning circuit, current conditioning circuit, switch conditioning circuit, RS485 communication circuit and can are designed based on the modular circuit design idea Communication circuit, voice alarm circuit, public address circuit, call circuit, clock circuit, charging circuit and other modular circuits, through the functional combination of each modular circuit, completed the design of each module hardware circuit. Experimental verification and functional test results show that the hardware circuit of each module has the expected function, works reliably and stably, achieves the expected design requirements, and lays a solid hardware foundation for the reliable and stable operation of the system.