The invention discloses a CPE (Chlorinated Polyethylene) foaming formula and a preparation method thereof. The CPE foaming formula comprises the following raw materials in parts by weight: 10 to 30 parts of EVA (Ethylene-Vinyl Acetate), 5 to 10 parts of CR (Chloroprene Rubber), 0 to 30 parts of POE (Polyolefin Elastomer), 10 to 30 parts of TPE, 1 to 3 parts of stearic acid, 1 to 2 parts of a bridging agent, 1 to 2 parts of zinc oxide, 1 to 2 parts of an AC foaming agent, 1 to 2 parts of an antioxidant and 1 part of toner. According to the CPE foaming formula disclosed by the invention, the aging resistance of CPE foaming is greatly increased, foaming is higher in elasticity and is lighter, more waterproof and mildew-proof and more antibacterial, cyclic utilization is achieved, recovery can be realized, the environment cannot be polluted, and more environment friendliness is realized; by adding the toner in mixing, all kinds of colors can be obtained through foaming, and the foaming is distinguished from traditional rubber foaming which just is black and maize-yellow, and compared with the rubber foaming, the cost is low.