Flexible joint of logging instrument

The utility model relates to a flexible joint of a logging instrument. The technical problem to be solved is to provide the flexible joint of the logging instrument, which has the characteristics that the structure is simple, the flexible connection among instruments can be realized, and jamming can be effectively prevented. The technical scheme which solves the problem is as follows: the flexible joint of the logging instrument is provided with an upper joint and a lower joint which are mutually connected; wherein a socket is coaxially arranged at the inner part of the upper joint by an upper screw plug, a plug is coaxially arranged at the inner part of the lower joint by a lower screw plug, the socket is connected with the plug by a bus, and oil filling holes are respectively arranged on the upper joint and the lower joint. The flexible joint of the logging instrument is characterized in that the upper joint is connected with the lower joint by a universal joint which cannot axially rotate. The flexible joi