The invention relates to the technical field of production of polyester fibers, in particular to a preparation method of a superfine denier moisture absorption and sweat release ice cool antibacterialfiber. The preparation method comprises the following steps: (1) preparing a polyester melt; (2) preparing a nanometer ice cool jade powder mixed with trace amount of the polyester melt; (3) preparing a cross-shaped cross section polyester fiber; and (4) winding and forming the polyester fiber. According to the preparation method of the obtained superfine denier moisture absorption and sweat release ice cool antibacterial fiber, a certain amount of the nanometer ice cool jade powder is added, so that the fiber achieves the antibacterial effect while the heat conductivity coefficient of the fiber is improved, and the fiber is mixed together with the cross-shaped cross section abnormal fiber, so that the fiber achieves the effects of transporting moisture, releasing sweat, cooling, and being antibacterial and bacteriostatic. In addition, the nanometer ice cool jade powder and a fiber-forming polymer are tightly combined, last permanently, and do not fall off even after the fiber is washed and worn for a long period of time, in addition, the superfine denier moisture absorption and sweat release ice cool antibacterial fiber is in contact with the skin for long, and has the effects ofimproving blood microcirculation, promoting metabolism, preventing diseases and eliminating fatigue.