Abstract: Based on a comparison of the advantages and disadvantages between the conventional API round thread and buttress thread,a new type of“Inverted Trapezium Wedge”like dovetail thread tooth,and an economical premium connection with ultra-high torque resistance are designed.Detailed here in the paper are the design,the processing and the inspection procedures of the said connection. Moreover the FEA program is used to calculate the stress and the strain of the thread as occurring during the make-up process. The analysis result demonstrates that after completely screwed up,all sides of the threads are fully engaged,and have a high contact stress so as to get the connection always have consistent stability of the threads mating under complex environment loading conditions.