Overcurrent protection circuit based on constant current power supply manner and control method thereof

The invention discloses an overcurrent protection circuit based on a constant current power supply manner and a control method thereof. The overcurrent protection circuit comprises a load current detection circuit, an error amplification circuit and a shunt circuit, wherein the error amplification circuit consists of an operational amplifier and a divider resistor; one input end of the operational amplifier is connected with the load current detection circuit to receive a current load current signal; the other input end of the operational amplifier is connected to a preset voltage terminal; and the output end of the operational amplifier is connected with the shunt circuit. By setting the load current detection circuit, the error amplification circuit and the shunt circuit, when input current exceeds a set value, an overcurrent shunt component is started to shunt the spare part of the current from bypass roads, and the current flowing through the overload is maintained into a safe set value, so that the load