The invention discloses an anti-aging plastic particle and a preparation method thereof and belongs to the technical field of plastic processing. The anti-aging plastic particle comprises polyethylene, ethylene propylene diene monomer, polycarbonate, polyetherimide, polyimide, an antioxidant, a flexibilizer, a stabilizer, a plasticizer, an anti-aging agent and the like. The preparation method comprises the steps of material preparation, blending, extrusion granulation, cooling, packaging and the like. According to the invention, polyethylene, ethylene propylene diene monomer and polycarbonateare adopted as raw materials to prepare the plastic particles; so that the tensile strength is high, the resilience force is high, and the flame-retardant performance is excellent; the anti-aging plastic particle disclosed by the invention has the advantages of simple preparation process, low production cost, suitability for mass production, high temperature resistance, dimensional stability, highstrength resistance, wide long-term use temperature range, excellent mechanical property and good fireproof property.