The processing technology of the spiral drill pipe joint was described，and the torsional characteristic of the joint was analyzed by means of software ABAQUS. The results show that the maximum Mises equivalent stress occurs on the geometry mutation, and is less than the yield limit. However, the Mises equivalent stress of female joint is 2.34 times that of the male joint, and the failure of female joint occurs easily under the repeated torsional condition, so the material of female joint should be strengthened preferentially. Furthermore, during torque transmission，only partial regions of the female and male joints are in contact and transmitted torque, and the rest regions are not mainly loaded regions without directly contact. The correctness of the simulation results is verified by torque experiment. Hexagonal joints can transmit bigger torque without damage, and the weld fracture occurs when the torque exceeds 10000 N·m.