IEZO protocol conversion module converts UART/SPI signal into CAN bus differential level to realize signal interface expansion and isolation. The protocol converter integrates microprocessor, CAN transceiver, power isolation and signal isolation. The product is compatible with UART/SPI interface, can be directly embedded into the device with UART/SPI interface, and expands more CAN communication interface on UART/SPI device to realize data communication between UART/SPI devices and CAN bus network.