The mainly of shale gas development are horizontal wells, due to fracture and bedding developed in shale formation, collapse and other wellbore stability problems can easily occur in the process of drilling long horizontal sections, as well as carrying rocks, friction and other issues; A lot of research work surface silicate drilling fluid inhibition is closer to the oil-based drilling fluid system, but it can be used during drilling horizontal wells in shale gas is worth exploring. On the basis of silicate drilling fluid system and shale stability analysis, the establishment of a potassium silicate drilling fluid system, beside a good suppression performance outside, the drilling fluid system having lower fluid loss (high temperature and high pressure loss is less than 6mL), and easy to control rheology, good lubrication, analysts believe that the system can meet shale gas horizontal drilling requirements.