The invention discloses a carrier signal transmission device of a three-phase four-wire intelligent meter without a null line. The carrier signal transmission device comprises a concentrator carrier signal transmission part and an intelligent meter carrier signal transmission part. The concentrator carrier signal transmission part comprises a concentrator, a concentrator three-phase line input end, a concentrator three-phase output end, a concentrator fuse protector, a concentrator capacitor and a concentrator null line. The intelligent meter carrier signal transmission part comprises an intelligent meter, an intelligent meter three-phase input end, an intelligent meter fuse protector, an intelligent meter capacitor and an intelligent meter null line. The device effectively solves the technical problem of the null line erection. In the aspect of materials, at 0.1 microfarads, a cost is about a few fen. Each one of bulk-purchased fuse protectors has a price of less than a few mao. The device has signal acquisition stability, a high success rate, can be installed conveniently and can be directly arranged at the tail of the intelligent meter in parallel. The device greatly shortens man-hour.