Preparation method of high-temperature-aging-resistant colored polyester industrial yarn

The invention provides a preparation method of high-temperature-aging-resistant colored polyester industrial yarn, and belongs to the technical field of melt spinning. Functional auxiliaries containing pigment components are mixed into polyester chips in a master batch mode, the high-temperature-aging-resistant colored polyester industrial yarn is obtained through screw extrusion melting and spinning, and the functional auxiliaries comprise a dispersing agent resistant to the high temperature of 200 DEG C or above, an antioxidant, a stabilizer, titanium dioxide, an antistatic agent, pigment and a PET matrix/PBT matrix. Comprising first-stage hot roller drafting, second-stage hot roller drafting, third-stage hot roller drafting and first-stage heat setting, the draw ratio of a spinning nozzle is 110-150, the draw ratio of the second-stage hot roller is 3.1-3.3, and the total drafting ratio is 4.5-4.1. According to the preparation method, the polyester industrial yarn is endowed with the characteristics of bein