Experiment device for testing fatigue life of threading connector of petroleum drill

The invention provides an experiment device for testing fatigue life of threading connector of petroleum drill, which comprises a base, a guide rail, a motor, a coupler, a floating bearing, an aligning roller bearing, a fixing end spring clamp, a bending moment applying device, a flexivity measuring instrument, a tail seat and a counter. Bending stress can be applied to the threading connector of the drill by the bending moment applying device based on four-point bending principle. The fixing end spring clamp is driven by the motor to rotate, so the threading connector of the drill can be rotated under certain torsion moment. Therefore, composite alternating stress working conditions of drill under well can be truly simulated. The experiment device is suitable for test research on fatigue life of full-size drill.