The invention discloses a processing technology for producing a flame-retardant granular material by utilizing waste textile fibers. The processing technology comprises the following steps: S1, removing particles and impurities in the waste textile fibers; S2, cleaning the waste textile fibers in the step S1 with clean water; S3, cleaning the waste textile fibers obtained in the step S2 with clearwater, and dehydrating and drying the waste textile fibers; S4, hardening the textile fibers; S5, grinding the hardened waste textile fibers into powder; S6, mixing the crushed waste textile fiber powder, calcium carbonate powder, an antioxidant, a plasticizer, a catalyst, glass fibers, a dispersing agent, a coloring agent, a stabilizer and a flame retardant; and S7, premixing the materials in the step S6 through a high-speed mixer, adding the mixed materials into a screw extruder, mixing the materials, and cutting the mixture into granules. In the invention, the processing technology is green and environment-friendly, resources are saved, the preparation method is simple, the cost is low, and the screw extruder used in the processing process can improve the granulation efficiency of theflame-retardant particles.