The invention relates to a surface mount method of mineralized collagen gradient coating for medical titanium implant. Based on the effect of voltage and electrolyte composition on in-situ biomineralization self-assembly of collagen in electrolyte, permineralized calcium phosphate layer, mineralized collagen layer and unmineralized pure collagen layer are assembled from the titanium substrate upward in profile by electrochemical codeposition technology. The components and structure of the above product are similar to those of natural bones. The product of good biocompatibility and biological responsiveness can accelerate the osteointegration of implanted area and shorten the period of treatment. The strong binding force between the coating and the titanium substrate prevents the occurrence of coating shedding due to friction stress during the process of implantation. The coating provided by the invention is applicable to clinical applications.