The present disclosure discloses a self-check chip of a leakage protector. The self-check chip includes a power-on reset circuit, used for resetting the self-check chip after being powered-on; a reference voltage module, used for providing a reference voltage for a comparator module; a bias circuit, used for providing direct-current bias for the reference voltage module, the comparator module and a ring oscillator; the comparator module, used for monitoring an open-circuit condition of a trip coil and the change of a thyristor anode voltage and generating a power frequency clock; the ring oscillator, used for providing a clock for a counting module and a digital processing module; the counting module, used for generating a self-check signal, a leakage trigger signal, a PHASE pin detection signal and a reset signal of the counting module and the digital processing module; a trip enabling signal generation module; and the digital processing module.