The recent research on high-density, large-capacity, nonvolatile holographic storage in photorefractive crystals, carried out at Beijing University of Technology, is reviewed in this paper. A batch thermal fixing technique was developed to overcome the volatility of a large number of multiplexed holograms, which has also proved to increase the effective dynamic range of crystals, hence to increase the storage density. The key of this technique is determination of the inter-batch optical erasure time constant that is much longer than the convenient (intra-batch) erasure time constant of the crystal. Disk-type storage is proposed to increase the degree of spatial multiplexing, so that the whole volume of the material can be used for storage, and the capacity increases remarkably. Incorporating batch thermal fixing into holographic disk storage yields to a track-division thermal fixing (TDTF) scheme for holographic disk storage to overcome the volatility of information and increase the storage density and capacity as well. Analyses and experimental results on a high density of 50 bits/μm~2 (10 Gbits/cm~3) show that high-density huge-capacity mass storage, indicated by storing 1 tera-bits or more data in a single crystal of reasonable size, can be achieved by means of TDTF holographic disk storage scheme.