The invention discloses a method for preparing a WC /
graphite composite coating on the surface of
titanium alloy. The method includes the steps that firstly, the surface of a
titanium alloy base material is pretreated so that an oxidation film on the surface is removed; secondly, WC
powder and
diamond powder are evenly mixed to obtain mixed
powder, a
polyvinyl alcohol aqueous solution is added into the mixed powder and stirred evenly, and a cladding material is obtained; thirdly, the cladding material is arranged on the surface of the
titanium alloy base material in advance, and a precoated layer is obtained after
drying; and fourthly,
laser cladding treatment is carried out on the surface of the
titanium alloy base material with the precoated layer, and the WC /
graphite composite coating is obtained through preparation. Polymorphism occurs to the
diamond in the precoated layer on the surface of the
titanium alloy base material through the heat generated in the
laser cladding treatment, and
graphite is generated after conversion. The defect that a graphite
coating can not be prepared through the
laser technology in the prior art is overcome, the WC /
graphite composite coating is prepared on the surface of the
titanium alloy, the abrasion resistance of the surface of the titanium alloy is improved, and the
friction coefficient of the titanium alloy is lowered.