Abstract: The present invention relates to an R-T-B based permanent magnet material, having a composition of RxTyTmqBz (at. %), wherein 13?x?15.5, 0.5?q?3, 0.85?z?1, y=100?x?q?z; wherein R is LRaHR1-a, LR is one selected from the group consisting of Pr, Nd, PrNd, or a combination thereof, HR is one selected from the group consisting of Dy and Tb, or a combination thereof, and 0.95?a?1; wherein T is one selected from the group consisting of Fe and Co, or a combination thereof; and Tm is a transition metal. The advantage of the method is that: plating a heavy rare earth film on alloy flakes using a magnetron sputtering device, and the coercivity of the magnet is significantly increased simply by having a “core-shell” structure without long time diffusion heat treatment.