Abstract: The deep dewatering and subsequent disposal of stocked sludge are the problems that restrict the development of landfills. Incineration is the most effective way to reduce the volume of sludge in landfill, and efficient deep dewatering is a necessary prerequisite for sludge incineration. Suction filtration curve, capillary water absorption time (CST) and moisture content of sludge cake were used as evaluation indexes to explore the effect of polyaluminum chloride (PAC)-quicklime-straw powder on deep dehydration of stockpile sludge, and to analyze the influence of various factors and the economic cost. In addition, the incineration characteristics of dehydrated sludge cake were analyzed by TG-DTG curve through thermogravimetry experiment. The results showed that the effect of various components in the combined conditioner on CST reduction of stocked sludge was PAC > quicklime > straw powder. PAC and quicklime promoted the transition from bound water to free water mainly by adsorption bridging or compressing the thickness of the electric double layer, while straw powder played an important role in the construction of skeleton structure during the process of pressure filtration. When the dosage of PAC, lime and straw powder (dry basis ratio) was 35%, 20% and 29%, respectively, the moisture content of sludge cake and CST were optimal, 56.3% and 47.9 s, respectively, and the economic cost advantage of the combined conditioner was significant. Compared with the original sludge, the ignition temperature of dehydrated sludge cake was higher. The addition of straw ensured the sustainable combustion of sludge in the combustion process. The maximum combustion loss rate (T_m) of dehydrated sludge cake reached 3.828%/min. The results showed that PAC-quicklime-straw could enhance the effect of deep dewatering by changing the chemical properties and pressure filtration properties of stocked sludge, and improve the combustion behavior of the dehydrated sludge cake, which was of great significance to the reduction and incineration of the stocked sludge.