An optical transceiver including a MDIO interface, a logic device, a first memory, a first bus, a second bus, and a microcontroller. The logic device includes configuration data and an internal circuit reconfigurable according to the configuration data, and is electrically connected to the second bus. The first memory is configured to store the configuration data and electrically connected to the first bus. The microcontroller is configured to receive new configuration data from the external device through the MDIO interface and write the new configuration data to the first memory through the first bus for rewriting the configuration data in the case of receiving an update command from the external device, and configured to read the new configuration data stored in the first memory through the first bus and send the new configuration data to the logic device through the second bus in the case that the optical transmitter is activated.