The invention provides a crosslinked polyethylene DC submarine cable DC-AC carrying capacity contrast test method, and relates to a submarine cable test method. Using a DC submarine cable to transmit alternating current has risk, and the alternating current transmission feasibility and applicability of a crosslinked insulating submarine cable cannot be verified. The method has the following steps of 2) setting the test environment; 2) setting temperature sensors; 3) installing a DC carrying capacity test loop; 4) measuring the DC cable carrying capacity; 5) installing an AC carrying capacity test loop; 6) measuring the AC cable carrying capacity; 7) post-test inspection; and 8) DC-AC carrying capacity contrast. According to the technical scheme, the difference of the DC-AC carrying capacity is verified by the electrical test method that alternating current is piped into the crosslinked polyethylene insulating DC submarine cable and the AC carrying capacity is obtained and then contrasted with the DC carrying capacity so that the alternating current transmission feasibility and applicability of the crosslinked insulating submarine cable can be verified from the perspective of test, the test operation is easy and the result is reliable.