The invention discloses a production process of moisture absorption and sweat releasing type polyester filament yarn. Polyester slices are crystallized in a crystallizer in advance, the polyester slices crystallized in advance are ventilated and dried, and the dried polyester slices are obtained; the dried polyester slices are put in a screw extruder to be melted and filtered to obtain melt; the filtered melt is put in a spinning box; the melt is metered through a metering pump and enters a spinning assembly to be extruded to form yarn; the yarn extruded from the spinning assembly is cooled to the room temperature and solidified into yarn bundles; the yarn bundles are wound through a winding machine for use in the next process. By changing the fiber interface form, grooves are formed in fiber longitudinal surfaces, the capillary effect of fabric is enhanced through the grooves, sweat is rapidly transferred to the surface of the fabric to be dispersed through the core absorption, diffusion and transmission effect by means of the fine grooves in the fiber surfaces so as to rapidly volatile, and therefore the dry touch of human skin is kept.