Leakage current detection circuit, method, device and system

The invention provides a leakage current detection circuit, method, device and system, the leakage current detection circuit comprises a communication module and a leakage current detection module, the communication module is connected between a battery and a device to be detected, and the leakage current detection module is connected in parallel with the communication module; wherein the leakage current detection module is used for detecting the leakage current of the to-be-detected equipment after the to-be-detected equipment is switched to a shutdown state; and the communication module is used for conducting before the leakage current detection module detects the leakage current of the to-be-detected equipment so as to connect the battery and the to-be-detected equipment. The communication module is arranged to ensure that the to-be-detected equipment is in a power-on operation state before the leakage current detection module detects the leakage current of the to-be-detected equipment, so that when the le