A salfaprodil freeze-dried powder injection, and a preparation method thereof and the use thereof are proposed. The preparation method may include adding salfaprodil into water for injection, filtering after the salfaprodil is completely dissolved, and adjusting pH of filtrate with an alkaline substance water solution. The method may also include adding the injection water to achieve a constant volume, filling with an inert gas for protection, and performing sterilization and filtration to obtain a salfaprodil solution, which is then freeze-dried to obtain the -salfaprodil freeze-dried powder injection.