The invention relates to a method for preparing L-2-aminopropanol by means of splitting DL-2-aminopropanol. The method includes steps of 1), dissolving L-
tartaric acid in water to obtain L-
tartaric acid aqueous solution; 2), dissolving the DL-2-aminopropanol in 
alcohol solvents at the 
room temperature, then stirring the DL-2-aminopropanol and the 
alcohol solvents under cooling conditions, simultaneously completely dropwise adding the L-
tartaric acid aqueous solution into the DL-2-aminopropanol to obtain 
mixed solution, then cooling the 
mixed solution until the temperature of the 
mixed solution reaches 0-5 DEG C, and preserving heat to obtain cooled solution; 3), adding a small quantity of 
crystal seeds into the cooled solution, allowing the cooled solution to stand still at the temperatures 
ranging from -15 DEG C to +25 DEG C, crystallizing the cooled solution at the temperatures 
ranging from -15 DEG C to +25 DEG C for 16-24 hours and separating out L-tartaric acid-L-2-aminopropanol 
acid salt crystals; 4), dissolving the L-tartaric acid-L-2-aminopropanol 
acid salt crystals by the aid of 
alcohol solvents, adding inorganic bases into the L-tartaric acid-L-2-aminopropanol 
acid salt crystals in batches, stirring the inorganic bases and the L-tartaric acid-L-2-aminopropanol acid salt crystals until amino alcohol is completely free, carrying out suction 
filtration and carrying out reduced-pressure 
distillation on filter liquid to obtain the L-2-aminopropanol. The method has the advantages that processes are easy to implement, raw materials are high in 
utilization rate, and accordingly the method is suitable for large-scale production.