The invention discloses a method for preparing a
nanoparticle coating with the bone induction and
antibiosis functions on the surface of a medical
metal. According to the method, nanoparticles with different
electric properties as used as a carrier, the nanoparticles are formed by mutual crosslinking of high-molecular polymers, and growth factors and
antibiotics are respectively loaded in the process of preparing the nanoparticles with dissimilar
electric properties, wherein factors and factor-friendly polyanions are sufficiently mixed to react first and are then immobilized into the nanoparticles through ionic crosslinking; and amino-containing
antibiotics are grafted to a polyaldehyde anionic
polymer through chemical crosslinking first and are then loaded into the nanoparticles through ionic crosslinking. The two types of nanoparticles are alternately assembled on the surface of the medical
metal through
electrostatic adsorption, covalent crosslinking is also formed among the particles, and the stability of the
coating is enhanced. The
coating prepared by using the method has the function of controlling adsorption and release of the growth factors and the
antibiotics under the normal physiological environment, the activity of the growth factors are keep well and a strong bone induction function is achieved; and in addition, the antibiotics can be slowly released for a long time, and a good
antibiosis effect is achieved.