The invention discloses a complex vitamin freeze-dried powder injection prepared from a lipid soluble vitamin, a water-soluble vitamin, a solubilizer and a plasticizer. The invention further discloses a preparation method of the complex vitamin freeze-dried powder injection. The method comprises the following steps: stirring the lipid soluble vitamin, the solubilizer and water for injection for dissolution, and then adding the water-soluble vitamin and the plasticizer, additionally adding the water for injection and keeping stirring for dissolution, and then adding activated carbon for adsorption, adjusting pH value, filtering, bottling, freeze drying, packing and sealing to obtain the finished freeze-dried powder injection. The complex vitamin freeze-dried powder injection employs few subsidiary materials, has simple preparation process, screens and optimizes the freeze-dried process in particular; has low production cost, safe and reliable quality, and is convenient to storage and transportation.