Abstract: In order to solve the difficult problems such as fracture leakage, well collapse, low mechanical drilling speed and so on in the process of drilling in the eastern margin of the Ordos basin, the paper analyzed the causes and features of these drilling difficulties from the geological conditions, using laboratory analysis and field test to put forward effective measures. To improve the overall development efficiency, cluster well group and well trajectory were optimized, drilling fluid system consisting of velvet pouch which maintains the stability of borehole wall and reduces reservoir damage was formulated. Aiming at fracture leakage, the tester of five parameters which can accurately determinate leakage point was developed. On this basis, with blocking slurry as research object and through practice, the blocking technology was formed for different leakage scale and rate. So far, the research results have been successful to guide the drilling of about 500 CBM wells in the area.