Well ZK1146 is a scientific drilling hole for Qilianshan gold mine, which is located in Jinying mining area of Gansu Province; the mining area contains formations of sandstone, mudstone, carbonaceous slate and phyllite with poor lithology and cementation, large dip angle, disordered bedding and low wall strength. Based on this situation, the solid free film-forming and anti-sloughing drilling fluid system was developed with inhibitory and cementation to solve the drilling difficulties in broken, collapse and water sensitive formations. Good effects of borehole wall and core protection have been obtained in well ZK1146, the mudstone dispersing is effectively prevented.