The utility model provides a logging instrument, includes: the instrument housing of integral tube -shape, the fast nut that revolves, install on instrument housing's surface the location, the inside one end at instrument housing is installed to pressure -bearing plug, location, the female, the inside and the one end that are located instrument housing are connected with the pressure -bearing plug, an installation section of thick bamboo is located instrument housing's inside, and mother inserts head position in between pressure -bearing plug and the installation section of thick bamboo, and the one end of installation tin is connected with the other end of female, the skeleton, inside and the one end that is located instrument housing is connected with the other end of an installation section of thick bamboo, be located the locking cap of installation cavity, first elastic component and plug, connect the shell, install on instrument housing's internal surface the location, and the other end of its one end and skeleton is connected, the other end is towards instrument housing's the other end, with public plug. This logging instrument simple structure, and after the series connection the high limit of each instrument of accurate positioning, save the accent to the vexation.