Method for coating film on surface of drill point and drill point coated with film

The invention discloses a method for coating a film on the surface of a drill point and a drill point coated with a film, wherein the method for coating the film on the surface of the drill point comprises the following steps: providing a drill point; cleaning the surface of the drill point, and heating the drill point; forming a coherent film on the surface of the drill point; forming a mixed film on the surface of the coherent film; and forming a non-crystalline diamond film on the surface of the mixed film so as to form a drill point coated with a film. The drill point coated with the film, which is manufactured by the method for coating the film on the surface of the drill point, comprises the drill point, the coherent film, the mixed film and the non-crystalline diamond film, wherein the mixed film comprises a non-crystalline diamond material and ingredients contained in the coherent film. In the mixed film, the further the part is from the drill point, the higher the content of the non-crystalline diamo