Abstract: Described here in the paper are the structural characteristics of the CB-SF-II extreme-line premium connection. The FE simulation method is used to analyze the typical working conditions of the service process of the said premium connection.Focused on are the connection efficiency, and the internal pressure resistance and collapse resistance of the premium connection under the composite load working conditions. And the full-scale test result is also described. The result shows that the connection’s connection efficiency has been more than 75% of the pipe body strength, and its torque resistance is far higher than that of the API thread connection with the same size.