The invention discloses a reinforced phase gradient distribution infiltrated silver-based electric contact material and a preparation method of the reinforced phase gradient distribution infiltrated silver-based electric contact material. The method comprises the steps that firstly, silver powder, reinforced phase powder and an additive powder body X are subjected to high-energy ball milling, anda composite powder body is prepared; secondly, the composite powder and the silver powder are mixed and screened, then the silver powder is added once more and mixed through a wet method, and colloidfor powder body pelleting is added; thirdly, the powder body obtained after mixing through the wet method is dried, pelleted and formed; and at least two-step pressing is adopted for forming, one layer is formed at each pressing, and the layers are arranged according to the density from large to small; and fourthly, a green body is subjected to colloid removal and infiltration. The reinforced phase of the prepared material is in a certain concentration gradient distribution from the working face to the welding face, the material resistance changes with variation of the concentration and continuously decreases, the stability of the whole contact resistance of a switch in the use process is guaranteed, the temperature rising is stable or lower, and the service life of the switch is prolonged.