Abstract: Disclosed is a method of simultaneously processing fly ash and COPR, which can treat the fly ash and COPR harmlessly during the landfilling process through biochemical and engineering measures. The method includes: transferring the fly ash and COPR to the yard; laying an impervious layer inside the yard; laying a diversion material at a bottom of the yard; laying a mixture layer on the diversion material, where the mixture layer contains a biogas residue, a waste carbon source, ferrous sulfate, a nutritional additive, the waste incineration fly ash and COPR; placing an internal-electrolysis ceramsite layer on the mixture layer; injecting a carbon source solution from an upper portion of the yard and collecting a leachate to a collection device through the diversion material irregularly during the operation; and recirculating the leachate to a top of the yard for spray reinjection.