With the development of Fuling shale gas exploration and development, the complex accidents become more prominent during long horizontal well drilling process. In Longmaxi formation, fracture developed, lithology was complex with serious breaking; mud density window was narrow, so it was prone to collapse with overflow and leakage and the lost circulation of oil-based mud was serious in the horizontal wells section. In order to quickly and safely drill through the complex shale layer, MPD technique（managed pressure drilling）was applied in Fuling shale gas field. MPD technique was used in Jiaoye well 33-4HF, some leakage loss display layers with different pressure coefficients were drilled in the long horizontal section, the final depth was reached successfully, the leakage of oil-based mud and the adverse effects were greatly reduced; as a result, economic loss was also reduced with distinct application effects.