The service life of the coated tool can be extended through the improvement of the bonding force between the diamond film and the tungsten carbide base The experimentation results show when the diamond film is deposited on the surface of tungsten carbide preplanted with diamond micro powder, not only will diamond grow outwards on the surface of the preplanted diamond in a homogeneous manner, but also grow on tungsten carbide through crystallization, which takes place alternately and exhibits good compatibility, resulting in a dense and uniform diamond film