The invention discloses a leakage positioning monitoring system of an annular sealing surface of a nuclear reactor pressure container. The system comprises a signal acquisition unit, a conditioning unit and a processing unit, wherein the signal acquisition unit is used for acquiring a sound emission signal acquired by the annular sealing surface of the nuclear reactor pressure container and transferring the acquired signal to the conditioning unit, the conditioning unit is used for performing electrical isolation, programmed amplification and bandpass filtering on the signal received by the signal acquisition unit and transferring the processed signal to the processing unit, the processing unit is used for acquiring an effective value of the sound emission signal of the annular sealing surface of the nuclear reactor pressure container according to the signal transmitted by the conditioning unit and judging whether the annular sealing surface of the nuclear reactor pressure container isleaked or not according to the effective value of the sound emission signal. By the system, the technical problem the annular sealing surface of the nuclear reactor pressure container cannot be effectively monitored in the prior art is solved, and real-time monitoring of the leakage of the annular sealing surface of the nuclear reactor pressure container can be effectively achieved.