The utility model relates to a emergency mechanical off-hand device capable of getting into thin-wall tail pipe. The device is capable of combining with a respective tail pipe hydraulic off-hand mode as its alternative emergency scheme. The utility model mainly comprises an outer tube, an outer tube extended tube, a middle tube and a loading tool top joint. The outer tube with a righting sleeve equipped on its top is wedged into and limited by a torque transmission slot through a outer tube ratchet; in the central shaft, by a shear pin and a shear pinhole, a locking-unlocking mechanism is fixed whose bottom end is connected with a ball-guiding sleeve by screw thread; both the outer tube and the central shaft have a plurality of ball sockets disposed correspondingly and locking is achieved by a locking ball; on the outer wall in the middle of the locking-unlocking mechanism, no less than one unlocking annular recess is arranged; on the top of the locking-unlocking mechanism, a step is formed and a clamp spring locking sleeve is installed by screw; on the tope of the loading tool, a clamp spring slot is formed into which the clamp spring is pressed. The utility model has the following advantages: the device is capable of rotating, lifting, dropping and cycling during getting-in; when the tail pipe hydraulic off-hand mode can not realize caused by clamp tail pipe complex condition or other reasons, the device is capable of realizing emergency mechanical off-hand with no influence to successive well cementing operations; the outer tube wall thickness is similar to that of the tail pipe, thereby the tail pipes leaved in the original hole of the four-level multi-bottom branch well during interpenetrate is easy to mill and interpenetrate the lower part of the well bore; and the device has simple operation, low cost and high reliability.