High-strength polyester fiber can replace traditional steel cables to make submarine cables. This study was testing the creep of high-strength polyester fibers ofonekind of denier yarns and three temperature and load ratios. Through the rupture time of creep tests, the rupture time of high load ratio and high temperature would beless than low load and low temperature. The change of temperature has a greater influence on the rupture time than the load ratio. It was found that the influence of variation of the rupture time, the load ratio was greater than the temperature change.