Abstract: As per ISO 13679 ∶2002,the EF simulation analysis and the full-scale evaluation test are performed to a certain type of the premium connection in a bid to evaluate the sealing ability thereof. As a result it is revealed that during the FEA process with the make-up/break off and load envelope tests as made to the premium connection,its equivalent stress is distributed rather homogeneously,and no more than the yield strength of the material,and that no structural failure and leakage are found with the extreme specimen during the full-scale evaluation test,which proves that the said premium connection is capable of having good connection strength and reliable sealing ability under complex load operation condition.