The moisture absorption and liberation properties of honeycomb micropore modified polyester fiber were studied. Through testing moisture absorption, liberation regains of honeycomb micropore modified polyester fiber, and normal polyester fiber in standard atmospheric conditions, their moisture absorption and liberation curves were depicted. The regression equations of moisture regains to time during their reaching, the balance of moisture absorption and moisture liberation were obtained according to the curves. Their moisture absorption and liberation rate curves were analyzed, and the regression equations of the rates to time were obtained. The results show that the moisture regain, initial moisture absorption rate, and moisture liberation rate of honeycomb micropore modified polyester fiber is much higher than those of normal polyester fiber with excellent performance of the moisture absorbance and sweat transportation properties of honeycomb micropore modified polyester fiber.