Mobile phone charger with built-in overvoltage and overload protection

The utility model discloses a mobile phone charger with built-in overvoltage and overload protection, which relates to the technical field of mobile phone chargers and comprises a shell, a circuit board is mounted in the shell, a USB interface is mounted on one side of the circuit board, one end of the USB interface penetrates through one side of the interior of the shell and extends into one side of the shell, and the other end of the USB interface is connected with the circuit board. And one side, far away from the USB interface, of the shell is provided with two insertion sheets. According to the utility model, the output voltage is detected through the miniature voltage sensor, the magnitude of the output voltage is detected through the miniature voltage sensor, if the output voltage is too large or too small, the miniature transformer can be turned on, and the voltage is stabilized to be normal under the action of the miniature transformer and then is output to the mobile phone battery through the chargi