Abstract: This paper reported a study on the tensile creep behavior of continuous?glass?fiber composites. To simulate the stress state of the composites in the pressure vessel and reduce the influence of clamping force, a tensile creep test method for annular specimens was developed. The tensile strength and tensile creep under different stress levels of composites were investigated. Based on the time?stress equivalence principle, the maximum creep stress of the composites with 50 years service life was fitted by a double logarithm method, which provides a technique support for the design of composite pressure vessels. Based on the time?stress equivalence principle, the maximum creep stress of composite is fitted by double logarithm method. In order to guarantee the service life of pressure vessel for 50 years, the maximum creep stress should be lower than 44.4 % of its tensile strength.