The invention relates to a preparation method of a wet process mixed natural rubber material. The method comprises the following steps of: preparing slurry and soaking 15-40 percent of dry white carbon black in 60-85 percent of deionized water; adding a coupling agent and a surfactant, uniformly mixing, grinding, preparing latex mixed liquor, extracting natural latex and adding white carbon black water dispersoid into the latex; stirring and mixing to obtain a latex mixed liquor, flocculating and adding acetic acid into the mixed liquor; performing rubber washing and dehydration by using a rubber washing machine and feeding to a rubber pelletizer for pelletizing; and feeding rubber particles into a box drying cabinet for drying. The preparation method has the advantages of simple machining process, small equipment investment, realization of various ideal performances with the most ordinary white carbon black, low dust pollution in the entire production process and energy saving. A tire manufactured with the method has small rolling resistance, low heat generation, high tensile strength, high tearing strength and high rubber material ageing resistance. Mixing of the white carbon black is performed in a liquid phase, so that the dispersivity and uniformity are enhanced.