The invention discloses plant infusion nutrient solution and a preparation method thereof and aims to provide nutrient solution which can be directly infused into the plants, stimulate the tree activity, promote the plants to rapidly take root and sprout, quickly supply nutrition to the trees, and enhance the tree stress resistance, and a preparation method of the nutrient solution. The proportion of the nutrient solution is that: every 1,000ml of deionized water contains 0.05 to 0.1g of monopotassium phosphate, 0.02 to 0.045g of potassium nitrate, 0.15 to 0.3g of calcium nitrate tetrahydrate, 0.11 to 0.2g of magnesium sulfate heptahydrate, 0.03 to 0.06g of ferrous sulphate heptahydrate, 0.07 to 0.15g of disodium ethylene diamine tetraacetate, 0.015 to 0.025g of manganese sulfate tetrahydrate, 0.012 to 0.018g of zinc sulfate heptahydrate, 0.04 to 0.06g of copper sulfate pentahydrate, 0.015 to 0.022g of ammonium molybdate, 0.015 to 0.02g of indolebutyric acid, and 0.008 to 0.015g of 6-benzylaminopurine. The plant infusion nutrient solution satisfies the needed nutrient in the process of transplanting big trees, has high absorption utilization ratio, quick response, stable form, high activity, and is easily absorbed by the plants.