A leakage current detection and protection device includes a leakage current detection module for generating a detection feedback signal when detecting a leakage current on the power supply lines, wherein the power supply lines supply a working power to the leakage current detection module during half of the AC power cycles; a self-test module for testing whether the leakage current detection module is faulty based on the detection feedback signal, which includes: a simulated leakage current generating circuit for generating a simulated leakage current signal; a fault signal generating module for generating a self-test fault signal when the leakage current detection module has a fault; and a self-test compensation module for supplying an auxiliary working power to the leakage current detection module so the leakage current detection module is in a working state whenever the simulated leakage current is generated. This prevents misjudgment by the leakage current detection module.