In the past 40 years, metal nanomaterials have developed rapidly. Because the special properties of metal nanomaterials differ from macroscopic crystals, they have gradually played indispensable roles in all walks of life. At present, human beings are facing increasingly serious ecological problems, such as lack of resources and environmental pollution. Therefore, the green ecological model combining metal nanomaterials with biology is an irresistible general trend. This article mainly focuses on the bio-green synthesis methods of the preparation of the metal and metal oxide nanomaterials with various plant extracts, microorganisms, proteins and other biological materials as reducing agents. These methods are easy to operate and utilize biological reagents with unique physiological structures, which are not only environmentally friendly, but can also limit the growth of nanomaterials, overcome the enormous surface energy, and prevent the enlargement of the metal nanomaterials in size and structure due to Ostwald ripening or agglomeration. In addition, the combination of specific structures of biomaterials with metal nanomaterials usually exhibits synergy or new physicochemical and physiological properties. The surface plasmon resonance of metal nanomaterials will be enhanced under laser irradiation and can emit energy in the form of heat, so it can yield unusually brilliant results in the treatment of tumors. At the same time, with the enhancement of surface plasmon resonance effect, the Raman scattering of the material can be significantly enhanced, so Raman scattering bioimaging can be used to monitor the condition of the upper tumor cells in conjunction with photothermal therapy. Bacteriostatic and antibacterial is a characteristic of most metals, so metal nanomaterials are regarded as a new class of antibacterial biological reagents. The difficulty of wound self-healing lies in bacterial infection, so metal nanomaterials with antibacterial properties have become candidates for treating wounds and other conditions. Many characteristics of metal nanomaterials can be used as media for identifying biological signals and converting them into photoelectric signals to monitor changes with instruments, which has more convenient operation and higher accuracy. Metal nanomaterials prepared from biomaterials can improve and supplement existing medical methods, and accomplish medical goals conveniently and effectively. The biochemical preparation of metal nanomaterials will bring more intersections between the nanometer and biological fields in the future. There will be more interdisciplinary workers to work hard on the existing challenges, and there will be an indispensable figure of metal nanomaterials in medical field in the future.