Magnesium phosphate biomaterial, as an alternative to well-known calcium phosphate biomaterials, is an excellent candidate for biomedical applications, owing to its outstanding biocompatibility and biodegradability. Herein, we report a simple strategy for the rapid synthesis of magnesium phosphate hydrate nanosheets (MPHSs) using the microwave-assisted hydrothermal method. This method is facile, rapid, surfactant-free and environmentally friendly. The product shows an excellent ability to promote osteoblast MC-3T3 adhesion and spreading, which indicates high biocompatibility. Moreover, the as-prepared MPHSs are explored for potential applications in the loading and release of the anticancer drug and protein adsorption, using docetaxel as a model anticancer drug and hemoglobin (Hb) as a model protein. The experiments indicate that the as-prepared MPHSs have a relatively high protein adsorption capacity and a high ability to damage tumor cells after loading docetaxel. Thus, the as-prepared MPHSs are promising for applications in various biomedical fields such as drug delivery and protein adsorption.