A charging conversion device, comprising: a first interface, a second interface, a charging module, a switch module, and a control module; wherein the first interface is used to connect to a charging device; the second interface is used to connect to an electrical device; the charging module is connected between the first interface and the second interface, and the charging module is electrically connected to the control module; the switch module is connected to the first interface, the second interface, and the control module, and the switch module comprises a first on state and a second on state; and the control module is configured to control the switch module to switch between the first on state and the second on state, and control the charging module to switch between an overvoltage protection mode and an output power adjustment mode; wherein in a case that the charging conversion device is connected to the charging device and the electrical device, if a first charging protocol supported by the charging device is same as a second charging protocol supported by the electrical device, or if the charging device does not have a fast charging protocol, the switch module is in the first on state, and the charging module is in the overvoltage protection mode; and if the first charging protocol and the second charging protocol are different, the switch module is in the second on state, and the charging module is in the overvoltage protection mode or the output power adjustment mode; characterised in that the control module comprises: a first integrated circuit, IC, chip and a second IC chip; the switch module is connected to the first IC chip and the second IC chip, and the first IC chip is connected to the second IC chip and the charging module; and the second on state comprises a first on sub-state and a second on sub-state; in the first on sub-state, the first interface is conducted with the second interface through the first IC chip and the second IC chip; and in the second on sub-state, the first interface is conducted with the second interface through the first IC chip; wherein in a case that the first charging protocol is different from the second charging protocol, and a voltage adjustment method corresponding to the first charging protocol is discrete adjustment, the switch module is in the first on sub-state, and the charging module is in the output power adjustment mode; and in a case that the first charging protocol is different from the second charging protocol, and the voltage adjustment method corresponding to the first charging protocol is continuous adjustment, the switch module is in the second on sub-state, and the charging module is in the overvoltage protection mode. the first interface is used to connect to a charging device; the second interface is used to connect to an electrical device; the charging module is connected between the first interface and the second interface, and the charging module is electrically connected to the control module; the switch module is connected to the first interface, the second interface, and the control module, and the switch module comprises a first on state and a second on state; and the control module is configured to control the switch module to switch between the first on state and the second on state, and control the charging module to switch between an overvoltage protection mode and an output power adjustment mode; wherein in a case that the charging conversion device is connected to the charging device and the electrical device, if a first charging protocol supported by the charging device is same as a second charging protocol supported by the electrical device, or if the charging device does not have a fast charging protocol, the switch module is in the first on state, and the charging module is in the overvoltage protection mode; and if the first charging protocol and the second charging protocol are different, the switch module is in the second on state, and the charging module is in the overvoltage protection mode or the output power adjustment mode; characterised in that the control module comprises: a first integrated circuit, IC, chip and a second IC chip; the switch module is connected to the first IC chip and the second IC chip, and the first IC chip is connected to the second IC chip and the charging module; and the second on state comprises a first on sub-state and a second on sub-state; in the first on sub-state, the first interface is conducted with the second interface through the first IC chip and the second IC chip; and in the second on sub-state, the first interface is conducted with the second interface through the first IC chip; wherein in a case that the first charging protocol is different from the second charging protocol, and a voltage adjustment method corresponding to the first charging protocol is discrete adjustment, the switch module is in the first on sub-state, and the charging module is in the output power adjustment mode; and in a case that the first charging protocol is different from the second charging protocol, and the voltage adjustment method corresponding to the first charging protocol is continuous adjustment, the switch module is in the second on sub-state, and the charging module is in the overvoltage protection mode.