Micro-holographic data storage is a bit-based volume holographic data storage technology. Localized micro-holograms are recorded at the focus of two counter-propagating beams, and each hologram represents a single bit that is subsequently read out by monitoring the reflectance of a single focused beam. The capacity can be 1 TB in a CD size disc using micro-holographic data storage technology together with hybrid multiplexing methods. It is easy to develop the compatibility of micro-holographic data storage system with the optical disc storage owing to their similar system structure. The basic concept and theoretical model of micro-holographic data storage are firstly illustrated, and then the research progress is reviewed mainly from the aspects including recording media, multiplexing technology and driving system, its future development is also pointed out.