Abstract: A bridge module for updating basic input/output system (BIOS) includes a universal series bus (USB) port and a series peripheral interface bus (SPI) port which are used to connect to a communication device and an electrical device respectively. The communication device stores a BIOS updating data and includes USB port. The electrical device includes a motherboard, a SPI port and a BIOS chip. The SPI port is electrically connected to the motherboard. The BIOS chip is electrically connected to the SPI port and stores a BIOS old data. The method includes the steps of making the bridge module connect to the communication device and the electrical device; and triggering updating process to make the communication device transmit the BIOS updating data to the electrical device through the bridge module to update the electrical device.