The invention discloses a preparation method of PtRu /
graphene nano electro-catalyst, comprising the following steps of: ultrasonically dispersing oxidized nano
graphite sheets into liquid polylol; then adding a
chloroplatinic acid solution and a
sodium acetate solution, sufficiently mixing, wherein the content of the oxidized nano
graphite sheets contained in a mixture is 0.3-1.1 g / L, the concentration of
chloroplatinic acid is 0.0004-0.002 mol / L, the concentration of
ruthenium chloride is 0.0004-0.0013 mol / L, and the concentration of
sodium acetate is 0.005-0.027 mol / L; transferring the mixture to a
microwave hydro-
thermal reaction kettle for
microwave hydro-
thermal reaction for 5-10 minutes; and filtering, washing and
drying to obtain the PtRu /
graphene nano electro-catalyst, wherein the
mass fraction of a PtRu
alloy contained in the PtRu /
graphene nano electro-catalyst is 20-40 percent, the
mass fraction of graphene is 80-60 percent, the
atomic ratio of the PtRu
alloy is Pt:Ru=1:2-1.5:1, and the liquid polylol is propanetriol or glycol. The preparation method has energy saving, fastness, simple process, and the like; and in addition, the prepared PtRu / graphene nano electro-catalyst has good electrocatalysis property for the oxidation of
methanol and
ethanol and is widely used as
anode catalysts of direct
methanol fuel cells.