Abstract: Diamond film is deposited in CH₄/H₂ system by microwave plasma chemical vapor deposition (MPCVD). Plasma parameters are measured by emission spectrometer. The internal stress of the grown diamond film is measured by Raman spectrometer. The surface and section morphology of the grown diamond film are measured by SEM. The influence of tungsten surface laser treatment on the adhesion of diamond film is explored through thermal shock test. The results show that laser treatment can release the stress of diamond film and enhance the adhesion between tungsten and diamond film;with the premise that the adhesion between tungsten and diamond film is greatly improved and the surface damage of tungsten slice is as small as possible, the cutting depth of tungsten slice surface is more appropriate at 0.035 mm.