The present invention relates to an all-in-one converter using a low-speed optical module on a high-speed switch. The present invention relates to the field of optical modules in optical communications. It provides a solution of using a 25G optical module on a 100G switch, and simultaneously enabling a 10G optical module to be used on a 40G switch. A first electrical interface of the converter is connected with a 100G/40G switch, which meets the requirements of SFF-8636 protocol and realizes the bidirectional transmission of signals from the switch to the converter. A second electrical interface of the converter is connected with the optical module, which realizes the module's bidirectional transmission from the converter to the optical module. There is a signal conversion circuit inside the converter, which makes the signals of the two electrical interfaces meet the requirements of their respective protocols. An MCU is integrated inside the converter, which can read information of EEPROM inside the module, making the converter more user-friendly.