The invention discloses a power burr signal detecting circuit and a detection method thereof. The detection circuit comprises a power supply anode, a power supply cathode, a comparator, a first capacitor and a second capacitor. The first input port of the comparator is connected with the power supply anode through the first capacitor. The second input port of the comparator is connected with the power supply cathode through the second capacitor. According to the power burr signal detecting circuit and the detection method, the burr signal of a power supply is collected through the capacitors, direct current voltage can be isolated, and thus there is no direct current power consumption. Through isolating direct current voltage, the change of the direct current voltage of an attacked power supply has no influence on the circuit in the scheme, and the detection circuit has the advantages of flexible use and strong portability.