The Well Jichengye-1 is located in Chengde City， Hebei Province， which is a small-diameter shale oil and gas survey well， with a structural location in the Lujiagou syncline of the Kuancheng Depression in the Yanliao Rift Trough of the Chengde Basin. The geological condition of the drilling project is extremely complex， with not only water inflow and leakage problems， but also loose and fragmented carbon powder sandy shale in the Hongshuizhuang Formation of the target layer， high montmorillonite content in the clay mineral composition， strong water sensitivity， and poor wellbore stability. Drilling construction poses risks of collapse， leakage， and drill sticking， which puts high demands on drilling technology and flushing fluid technology. In view of this， a detailed analysis was conducted on the performance requirements of each well section for the flushing fluid in the encountered strata. A dedicated flushing fluid system for Well Jichengye-1 was developed and formulated. Orthogonal experiments were conducted on the flushing fluid ratio for the target shale layer， and the flushing fluid formula was determined as follows： water+3% Na-B+3%（soil weight） Na₂CO₃+3% KHM+1% GPC+0.2% K-PAM+0.2% Na-CMC+1.5% MSDS. Tailored flushing fluid maintenance measures were carried out， which has good application results in the actual drilling process， and can provide reference for similar drilling projects.