Abstract: By 2020， the 13th Five-Year Plan for the Construction of National Urban Domestic Waste Harmless Treatment Facilities will basically realize the complete incineration of municipal solid waste（MSW） and zero landfill of raw waste. At that time， the landfill site of MSW will be facing ecological control. The fly ash produced by the incinerator will need to be filled and disposed. The fly ash landfill site will be designed to be built in the landfill site of MSW， which can effectively solve this problem and save land space. However， considering the high compressibility of MSW， the uneven settlement of the lower MSW dump is easy to occur under the action of the upper fly ash surcharge， which causes the unstable sliding of the fly ash dump and the MSW dump， and the destruction of the impervious membrane at the bottom of the fly ash reservoir area. Therefore， the stability analysis should be carried out in advance to evaluate whether the fly ash landfill area can be built on the domestic waste dump. Finally， the stability of a fly ash reservoir project to be built on domestic waste dump was analyzed， and its feasibility was evaluated.