The utility model discloses a casing joint who contains high strength moment of torsion screw thread, external screw thread and internal thread including the setting of sleeve pipe tip, the external screw thread thread sets up to the trapezium structure, and its top is graphic?settings, the planar axial width size of external screw thread thread increases from the port in proper order, interval size between per two external screw thread threads reduces in proper order, the internal thread thread sets up to the trapezium structure, and its top is graphic?settings, the planar axial width size of internal thread thread is agreed with the setting mutually from port and external screw thread and is increased in proper order, interval size between per two internal thread threads is agreed with the setting mutually with the external screw thread and is reduced in proper order. The utility model discloses make the screw thread realize the performance of highly resistance moment of torsion, guarantee that the screw thread can not lead to threaded connection to become invalid because of crossing the moment of torsion or owing the moment of torsion, have joint strength simultaneously and reach the characteristics that the leakproofness is high well, be applicable to highly deviated well and horizontal well exploitation process.