An overvoltage protection apparatus, comprising: a determining unit, having an input end connected to an input end of the apparatus and an output end connected to an input end of a soft-start unit, and configured to determine whether an input voltage (Pin) at the input end of the apparatus exceeds a preset protection voltage, and send a result of the determining to the soft-start unit; and the soft-start unit, wherein an input end of the soft-start unit is separately connected to the output end of the determining unit and the input end of the apparatus, and an output end of the soft-start unit is connected to an output end of the apparatus, and if the determining unit determines that the input voltage (Pin) does not exceed the preset protection voltage and remains stable in a preset delay time, the soft-start unit delivers the input voltage (Pin) to the output end of the apparatus; otherwise, the soft-start unit does not deliver a voltage signal to the output end of the apparatus characterised in that the determining unit comprises: a first transistor having a source connected to the input end of the apparatus and a drain connected to the input end of the soft-start unit; a Zener diode having a positive electrode connected to a gate of the first transistor and a negative electrode connected to a ground terminal; and a second resistor, connected between the source and the gate of the first transistor; and the soft-start unit comprises: a second transistor having a source connected to the input end of the apparatus, a gate connected to the drain of the first transistor, and a drain connected to the output end of the apparatus; a first resistor, connected between the gate of the second transistor and the ground terminal; and a capacitor, connected between the source and the gate of the second transistor. a determining unit, having an input end connected to an input end of the apparatus and an output end connected to an input end of a soft-start unit, and configured to determine whether an input voltage (Pin) at the input end of the apparatus exceeds a preset protection voltage, and send a result of the determining to the soft-start unit; and the soft-start unit, wherein an input end of the soft-start unit is separately connected to the output end of the determining unit and the input end of the apparatus, and an output end of the soft-start unit is connected to an output end of the apparatus, and if the determining unit determines that the input voltage (Pin) does not exceed the preset protection voltage and remains stable in a preset delay time, the soft-start unit delivers the input voltage (Pin) to the output end of the apparatus; otherwise, the soft-start unit does not deliver a voltage signal to the output end of the apparatus characterised in that the determining unit comprises: a first transistor having a source connected to the input end of the apparatus and a drain connected to the input end of the soft-start unit; a Zener diode having a positive electrode connected to a gate of the first transistor and a negative electrode connected to a ground terminal; and a second resistor, connected between the source and the gate of the first transistor; and the soft-start unit comprises: a second transistor having a source connected to the input end of the apparatus, a gate connected to the drain of the first transistor, and a drain connected to the output end of the apparatus; a first resistor, connected between the gate of the second transistor and the ground terminal; and a capacitor, connected between the source and the gate of the second transistor. a first transistor having a source connected to the input end of the apparatus and a drain connected to the input end of the soft-start unit; a Zener diode having a positive electrode connected to a gate of the first transistor and a negative electrode connected to a ground terminal; and a second resistor, connected between the source and the gate of the first transistor; and the soft-start unit comprises: a second transistor having a source connected to the input end of the apparatus, a gate connected to the drain of the first transistor, and a drain connected to the output end of the apparatus; a first resistor, connected between the gate of the second transistor and the ground terminal; and a capacitor, connected between the source and the gate of the second transistor. a second transistor having a source connected to the input end of the apparatus, a gate connected to the drain of the first transistor, and a drain connected to the output end of the apparatus; a first resistor, connected between the gate of the second transistor and the ground terminal; and a capacitor, connected between the source and the gate of the second transistor.