Abstract: CBM fracturing effect has many influencing factors. Development effect with the same technology is different in different area. Based on a large amount of geological and engineering data in Shizhuang block, it was found that high geo-stress affects fracture extension and support in CBM fracturing, and difference between horizontal stress affects fracture direction and morphology. Coal seam with poor coal structure can produce large amount of gum during fracturing, which will block the diversion channel and result in poor fracturing effect. Engineering factors affecting fracturing effect mainly include the fracturing fluids performance, displacement, prepad fluid proportion and hole enlargement ratio. Finally, a serie of optimized technique was proposed, including "2%KCl+water, ladder displacement injection, prepad fluid volume 180-240 m³, perforation optimization and hydraulic networks fracturing". It was pointed out that the well pattern of CBM fracturing was important to fracturing effects and economics. Field practice shows that the research results have strong guiding significance for CBM development.