The invention discloses a medical stainless steel material and a preparation method thereof. The medical stainless steel material has the functions of bacterial adhesion resistance and promotion of osteoblast growth and comprises a medical stainless steel matrix, a first adhesive layer and a second adhesive layer, wherein the first adhesive layer is a 3-(methylacryloyloxy) propyltrimethoxysilane adhesive layer; the second adhesive layer is a polyethylene glycol compound adhesive layer. The first adhesive layer is introduced to improve the adhesive capability of the polyethylene glycol compound on the surface of the stainless steel to prevent falling off; the second adhesive layer is introduced to utilize the polyethylene glycol compound to improve the bacterial adhesion resistance of the stainless steel, so as to avoid that the bacteria are adhered and proliferate on the surface of the stainless steel. According to the invention, a molecular imprinting method is utilized during the process that the polyethylene glycol compound adhesive layer is introduced, so as to enable the stainless steel material to achieve a function of effectively identifying the osteoblast molecules and help the osteoblast to be fixed and grow on the surface of the material.