Nuclear power plant buried pipeline cathode protection effectiveness monitoring system

The invention belongs to the technical field of nuclear power maintenance and particularly relates to a nuclear power plant buried pipeline cathode protection effectiveness monitoring system. According to the nuclear power plant buried pipeline cathode protection effectiveness monitoring system, the difference between the on-potential and the off-potential of a test block can comprise the ohmic drop generated by an impressed current cathode protection system in the testing process and can further comprise the ohmic drop generated by a sacrificial anode system and disturbance of other stray currents, and therefore, by means of the difference between the on-potential and the off-potential of the test block, the ohmic drop generated in the testing process can be determined in a more-comprehensive manner under the circumstance that a to-be-tested pipeline cannot be disconnected from a sacrificial anode; and furthermore, the cathode protection potential of the determined to-be-tested pipeline can reflect the actua