The invention discloses an NKT cell preserving fluid. The preserving fluid comprises a solution medium and additives, the solution medium is a sodium chloride solution with a mass concentration of 0.9%, and the additives are hydroxyethyl starch, D-mannitol, human serum albumin, cinnamamide, meprobamate, zinc 2-hydroxysuccinate and L-glutamine. According to the NKT cell preserving fluid provided by the invention, the components such as the cinnamamide, the meprobamate and the zinc 2-hydroxysuccinate added in the NKT cell preserving fluid have a synergistic effect, a stable preserving environment is provided for cells, temporary preservation of the NKT cells at 4-6 DEG C is realized, the preservation time of the NKT cells is prolonged, and the preserved NKT cells are high in viability, can quickly recover activity and fully meet clinical requirements. DMSO is not used in the preserving fluid, and the use amount of human serum albumin is reduced, so the safety of the preserving fluid is better. The invention further provides an NKT cells preserving method. The preserving fluid provided by the invention is adopted, the operation is simple and convenient, the preservation cost is effectively reduced, and convenience is provided for short-distance transportation of the NKT cells.