The invention relates to an oil-immersed current transformer insulation discharge pulse detection device. The device comprises an opening cross-core type current sensor, the opening cross-core type current sensor is connected with a processor through signal wire, the processor is connected with a photoelectric converter through optical fiber, the photoelectric converter is connected with a USB (universal serial bus) interface, two semicircular parts are hinged to form the opening cross-core type current sensor, wherein one semicircular part is connected with the processor through a Z-shaped fixing part, and the other semicircular part can be freely opened and closed. The insulating paint has good adhesive force, the surface drying speed is fast, the peeling and seasoning crack are difficult, the impact resistance is strong, the high and low temperature resistance and water resistance are good, the insulating property is excellent and cannot be weakened as time goes by, the insulating paint has the advantages that the safety factor is high and the service life is long, and the detection device can be conveniently used for maintaining an insulated protective layer in the process of long-term use. The oil-immersed current transformer insulation discharge pulse detection device further has the advantages that the structure is simple, and the overhauling and maintenance are convenient.