Abstract: in order to solve the leakage of the coalbed methane driing, el al unstability,gas cutting and oter well completion difiulis in Mabi Block with an ndoor contrast experiment,the coal rock uniaxial compressive strength injected with thveed lling liquids and the licud pressure size of the cal nd rock sealed were measured.The experiment study results showed that with the injection of the potassium chloride sotution.the cal and rck srength was reduvced by 19.2%.ith th itj cton of the solid phrase polymerthe rilin licuid was reduced by 115%.with the inectio of the fuzz a . he drlig liuid could e inceased by 38.4%.with the ine cton of the fuzzy al riling licuid,the liquid pressure of the coal and rock sealed would be over 2』 4Pa.with the inj cion ofthe potassum chloride soutien and low sold phrase polymer drling liouid .the licuid pressure would only be 1.51 and 8 04 MIPa indidull:The fuzzy ball rilin liquid showed a highcolapse prevenion and leakage preventon capacity.The site application resuts were all same and the fuzz)ball iling liquid ofthe calbted methane coud met the repurement ofthe stabe wel wall nd the leakage prevention and leakage sealed.Theconstruction technicue with the naintenance umiber increased and the each maintenance volume reduced applied could solve the difficulties of the coalbed methane drilling in Mabi Block.