The research progress of nano-hydroxyapatite and its composite biomaterials, which are widely used, is summarized. The preparation techniques and applications of nano-hydroxyapatite and its composites in tissue engineering scaffolds, sustained and controlled release drug carriers, targeting drug delivery and environmental functional materials show that nano-hydroxyapatite and its composites will have good prospects in the field of biomedicine. The nano-hydroxyapatite composite biomaterial is a first phase or multi-phase material added to the nano-hydroxyapatite to obtain a favorable histological reaction, satisfactory strength and rigidity, and to synthesize a scaffold material for tissue regeneration. As a scaffold for guiding bone tissue regeneration, nano-hydroxyapatite composite material can also be used as a targeted drug release system for drug delivery system. It has good biocompatibility and degradability and has become a research hotspot in bone tissue engineering. The complex is expected to be applied to medical diagnostic fields such as tumor cell detection and nano biological probes.