In order to detect the fault types of 110kV XLPE photoelectric composite submarine cable across a certain strait

a diagnosis method of using the fibers in the cable is proposed.In this method

the IEC standard

Power Systems Computer Aided Design（PSCAD）software and ANSYS software are first used for the calculation and simulation of the temperature of the submarine cable in different faulty conditions.Then

the fiber temperature data are extracted from this cable temperature data

the fiber temperature changes in different faulty conditions analyzed and the relationship between the fiber temperature changes and the cable fault types derived.Finally

the effects of the fault position on the fiber temperature changes are analyzed.The analytical results show that this method can successfully detect the fault types of submarine cables and has significant reference values for their fault detection.