The invention discloses a method for quickly preparing a single-phase delafossite structure CuFeO2 microcrystalline material. The method comprises the steps that Cu(NO3)<2>.3H2O and Fe(NO3)<3>.9H2O are added into deionized water according to the mole ratio of 1:1, magnetic stirring for dissolving is conducted, and thus a mixed solution is obtained; a NaOH solution is dropwise added into the mixedsolution drop by drop, and then ultrasonic stirring and magnetic stirring are conducted in sequence; n-propanal is added into the solution dropwise, and then magnetic stirring is continued till colloidal suspension is formed; and the colloidal suspension is added into a microwave digestion tank, the filling rate of the colloidal suspension is 10-35%, microwave heating is conducted after sealing, after reaction is completed, a reaction product is naturally cooled to the room temperature, the microwave digestion tank is opened to take the reaction product out, and the reaction product is washedand dried to obtain the single-phase delafossite structure CuFeO2 microcrystalline material. According to the method, the reaction time is extremely short, energy consumption is less, operation is easy, technological parameters are easy to control, pollution is avoided, the yield is high, grains are developed completely, particle size distribution is even, and the single-phase delafossite structure CuFeO2 microcrystalline material can be widely applied to the fields of photocatalysis, photovoltaics, transparent conductive oxide, ferroelectric and the like.