The invention relates to a landfill sludge treatment method. The method comprises the following steps: sampling and analyzing sludge, determining the pH value, the type of smelly pollutants, the landfill depth and the horizontal distribution of the sludge, preparing an oxidation preparation, injecting the oxidation preparation into underground sludge by virtue of in-situ mixing and stirring equipment, and simultaneously stirring the oxidation preparation and the sludge underground by virtue of an impeller stirring head of the in-situ mixing and stirring equipment; after uniform stirring, carrying out standing reaction for 3.5-5.5 hours, and putting a curing agent into sludge by using an engineering machine, and stirring continuously by using the in-situ mixing and stirring equipment; afteruniform stirring, standing for 24-48 hours, carrying out open type excavation and transfer on the solidified sludge. By sequentially carrying out in-situ treatment and excavation, the construction operability is strong, the investment cost of the equipment is low, the treatment period is short, the treatment is thorough, the secondary pollution is avoided, the problem of stink pollution in the excavation process of the sludge is solved, and meanwhile, the treatment of the sludge is realized; and the method has relatively good economic and social benefits.