A detection circuit for control pilot abnormality of a DC charging pile, which is electrically connected to a control pilot signal generating circuit and a control circuit, providing instant protection for the DC charging pile while control pilot (CP) abnormality been detected. The detection circuit includes a control pilot (CP) signal potential discrimination module, a charging-discharging module electrically connected to the CP signal potential discrimination module, and a controller protection triggering module electrically connected to the charging-discharging module, wherein the CP signal potential discrimination module justifies the voltage level of the input CP signals been input, activates the charging-discharging module to charge the CP signals to a steady-state voltage higher than a predetermined voltage level within a certain time period, and activates the controller protection trigger module to provide instant protection for the DC charging pile.