The present invention relates to the technical field of leakage protection, in particular to a leakage current detection circuit and a device thereof. The connected S1 inductive terminal and the S2 inductive terminal can be signal-connected, and the driving module detects whether the S1 inductive terminal and the S2 inductive terminal are connected by a signal. There is a connection signal to judge whether there is leakage, and the drive module turns the switch module on or off to control whether the circuit breaker generates a circuit breaker signal, and then the main switch S can be disconnected when leakage occurs to ensure the safety of electricity use. There is no need to set up a transformer. Reduced volume, simple circuit structure, and easier production.