The invention provides a polypropylene-based macromolecular gradient functional material and a preparation method thereof. The material is a gradient functional material formed by diffusing alpha or beta crystal nucleating agent along a given direction at the molten state of a polypropylene-based material and enabling the alpha or beta crystals to be distributed at a concentration gradient along the direction when the polypropylene-based material is formed. The preparation method comprises the following steps: firstly preparing a polypropylene base material and a macromolecular polymer carrier loaded with a nucleating agent, and then molding the two materials in a case that the outer surfaces are laminated. The gradient functional material has the characteristics of the gradient functional material that alpha or beta-crystals are distributed in a gradient-concentration manner in the polypropylene base material, has no apparent interface, and is simple in preparation method, controllable in gradient structural characteristics of the product in the production process and suitable for popularization.