The utility model relates to a sensor field, in particular to butt joint type current sensor and supplementary preparation frock thereof. Butt joint type current sensor includes two semiorbicular casings, is equipped with semiorbicular skeleton in the casing, is equipped with the coil on the skeleton, the tip of skeleton is equipped with and is used for making the splint location fit of frock so that two skeletons dock into circular shape skeleton location structure with supplementary, and skeleton location structure is in the outside of coil. Compare with present butt joint type current sensor manufacturing method, the utility model discloses a butt joint type current sensor docks into two skeletons through supplementary preparation frock in when preparation circularly, then winds to twoskeletons, has improved wire -wound even degree, puies forward high pressure heater work efficiency rate simultaneously, the problem that machining efficiency is low that the coiling complicacy of having solved present butt joint type current sensor caused.