The invention provides a preparation method of an 
insulin glargine injection and the 
insulin glargine injection prepared by using the preparation method. The preparation method comprises the following steps: dissolving 
glycerol into part of water for injection to prepare a 
glycerol solution, then dividing the 
glycerol solution into three parts, and respectively adding 
insulin glargine, 
metacresol and 
zinc chloride; firstly uniformly mixing an 
insulin glargine-glycerol solution and a 
metacresol-glycerol solution to obtain a 
mixed solution I; then adding a 
hydrochloric acid solution into the 
mixed solution I until the pH value is equal to 3.0 to 3.5, then adding a 
zinc chloride-glycerol solution, uniformly stirring, and then adding a 
sodium hydroxide solution until the pH value is equal to 3.5 to 4.5; and finally stabilizing the volume to reach a final volume by using the water for injection. By adopting the preparation method provided by the invention, 
insulin glargine and other auxiliary materials can be rapidly dissolved, the preparation 
cycle time can be significantly shortened, process impurities produced in a preparation process can be reduced, the quality of the 
insulin glargine injection can be improved, the process 
energy consumption can also be reduced, and the production efficiency can be improved; and the preparation method can be more suitable for the requirements of large-scale production.