The present disclosure provides a high-voltage interlock system and a detection method thereof. The high-voltage interlock system includes a target control device and at least one non-target control device connected in sequence. The target control device includes a detection unit, a current generation controller, a current generator, and a second high-voltage component. A controller in the target control device generates a pulse drive signal for driving the current generation controller, receives a detection result signal output from a current detector, and determines a fault of a high-voltage interlock circuit according to the detection result signal; the current generation controller generates an alternating voltage signal according to the pulse drive signal; the current generator outputs an alternating current signal according to the alternating voltage signal; the current detector acquires a voltage signal across a detection resistor set and outputs the detection result signal.