An leakage current detection and protection device includes a leakage current detection module for detecting a leakage current on the power supply lines and generating a detection feedback signal in response thereto, a self-test module for testing whether the leakage current detection module is faulty, and a trip module for disconnecting the power supply lines in response to the self-test fault signal. The self-test module includes a simulated leakage current trigger circuit for generating a simulated leakage current trigger signal, a simulated leakage current generating circuit for generating a simulated leakage current signal in response to the simulated leakage current trigger signal, a trigger signal turn-off module for turning off the simulated leakage current trigger signal in response to the detection feedback signal, and a fault signal generating module for detecting a fault in the leakage current detection module and generating a self-test fault signal in response thereto.