The invention discloses closed-loop on/off submodule test equipment for a direct current circuit breaker. The test equipment comprises a test controller, a communication interface DBC&VBC, an integration driver and a testing circuit, wherein a user instruction is received through the test controller; according to the user instruction, a control signal is correspondingly output to the testing circuit and the communication interface DBC&VBC to drive the testing circuit and the communication interface DBC&VBC to output various types of signals to trigger the main branch or transfer branch submodule of a direct current circuit breaker to be tested; the main branch or transfer branch submodule of the triggered direct current circuit breaker outputs a corresponding voltage or current signal; andthe test controller obtains the signal through the testing circuit to be analyzed so as to realize the judgment of the state of the direct current circuit breaker. The test equipment has the advantages of being simple, easy in implementation and convenient in operation, can test a full-bridge module and a mechanical switch and has a wide application scene.