Trehalose is considered to be a biocompatible CPA that can replace glycerol in red blood cells(RBCs) cryopreservation, but it is difficult to enter the RBCs to provide protection. Various methods of loading trehalose into RBCs were summarized, including thermal stress method, osmotic shock method, liposomes method, etc. The principles, loading effects, advantages and disadvantages of those methods were introduced in detail. The mild loading scheme without membrance pores had advantages. Also, multiple methods can be attempted to improve loading efficiency and protective effect. Finally, the development trend of RBCs cryopreservation in the future was prospected in this review.