Preparation method of plastic product with excellent mechanical property

The invention relates to a preparation method of a plastic product, and particularly relates to a preparation method of a plastic product with an excellent mechanical property. The plastic product is made by machining 50 to 70 parts by weight of plastic particles and 30 to 50 parts by weight of calcium carbonate packed masterbatches; the calcium carbonate packed masterbatches are machined from the following raw materials in parts by weight: 50 to 70 parts of calcium carbonate, 10 to 30 parts of resin, 1 to 5 parts of octadecanoic acid, 5 to 10 parts of thermoplastic elastomer, 0.5 to 3 parts of organobentonite, 0.5 to 2.5 parts of titanate coupling agent or aluminate coupling agent, 5 to 8 parts of isopropyl alcohol and 0.5 to 2 parts of antioxidant; the calcium carbonate packed masterbatches prepared by the method provided by the invention can meet different additive amount requirements, for example, very high dispersity is stilled kept when an additive amount is about 50 percent, the plastic product prepared by injection molding is uniform in the mechanical property, the anti-pressure ability is greatly improved, and the appearance of the plastic product is flawless.