The invention discloses a preparation method of tobacco Maillard essence based on waste tobacco powder. The preparation method includes the steps: 1) weighing a certain amount of waste tobacco powder, mixing the waste tobacco powder with buffer solution, adding alpha-amylase and beta-amylase, adjusting the pH (potential of hydrogen) value of the buffer solution and performing reaction at the temperature of 45-65 DEG C for a certain time to obtain concentrated solution; 2) performing Maillard reaction for the concentrated solution and a certain weight of amino acid in water-propanediol solvents with the water content 10%-25% in a reaction system to obtain the tobacco Maillard essence; 3) dissolving the prepared tobacco Maillard essence in edible alcohol and then uniformly spraying the tobacco Maillard essence onto low-grade cut tobaccos. Smoking results indicate that cigarettes have fragrance of baked fragrance, caramel fragrance, cocoa fragrance and the like after the tobacco Maillard essence is added, smoking flavor is increased, smoke is exquisite and elegant, and the cigarettes are clean in taste. The preparation method is simple in technological process and low in cost, the smoking quality of the low-grade cigarettes can be obviously improved, and tobacco waste can be reasonably and comprehensively used.