The invention relates to an aqueous solution for preparing a stable complex vitamin composite, a complex vitamin composite injection and a preparation method thereof. The composite is prepared from 11 vitamins, or analogs thereof, racemization alpha-tocopherol, polysorbate and medically acceptable auxiliary materials by the freeze drying technology, wherein 11 vitamins comprises vitamin A palmitate, vitamin D3, vitamin C, cocarboxylase tetrahydrate, riboflavin sodium phosphate, vitamin B6, vitamin B12, folic acid, dexpanthenol, biotin and nicotinamide. Compared with the prior art, the composite has better stability.