The invention discloses a substrate carrier type slow-release urea based on rare earth modification enhancement and a preparation method thereof. The substrate carrier type slow-release urea based on rare earth modification enhancement searched according to the invention mainly comprises conventional urea, slow-release carrier filler and rare earth; the slow-release carrier filler includes polyacrylamide and a composition; the composition is at least one of crushed lignin, straw, attapulgite and bentonite; the effective components of the substrate carrier type slow-release urea include, by weight: 71-99.97 parts of the conventional urea, 0.01-20 parts of the composition, 0.01-4 parts of polyacrylamide, and 0.01-5 parts of rare earth. The nutrient loading capacity and nutrient slow-release performance of the substrate carrier in \ slow-release fertilizer are improved, utilization rate of the fertilizer is increased, the effectiveness of rare earth elements is improved, the growth and development of plants is benefited, and plant stress tolerance is improved; in addition, the modification process related herein is simple and has a promising application prospect.