The invention provides a method for strengthening methane oxidation of a covering layer of a landfill site and relates to a method capable of enriching methanotroph microbe inside mineralized garbage. The method comprises the following steps of: weighting sugar in proportion of adding 0.5 to 3kg of sugar into 1 ton of the mineralized garbage; adding 1 to 3 mass parts of sugar into 100 mass parts of water, stirring the mixture to prepare sugar solution, and adding the sugar solution into the mineralized garbage; uniformly mixing the mixture, and acclimating the mixture for 7 to 10 days to obtain a covering layer material; and finally, uniformly spreading the covering layer material on the surface of the domestic garbage through the conventional covering process according to 40 to 60cm of thickness of a final covering layer after a domestic garbage landfill unit finishes operation. The methane oxidation efficiency is improved to 810g/(m2.d) through detection. The method realizes treating waste with waste, has low cost, improves the methane oxidation efficiency by 2 to 3 times compared with common covering materials of the landfill site, and realizes emission reduction of greenhouse gases of the landfill site. The method has obvious social benefit and economic benefit, can be widely used for the domestic garbage landfill site, and is particularly suitable for strengthening methane oxidation covering layers of medium-sized and small domestic garbage landfill sites.