Abstract: The design of proper drilling fluid density in the hole, combining with the analysis on the creep tendency of salt bed is the key for successful drilling in the gypsum-salt formation. Based on the study of salt bed mechanics, the phenomena of hole instability in the gypsum-salt bed, especially in the deeper formation caused by unsuitable mud density is investigated, and a gypsum-salt bed creeping-pressure calculating model is proposed therefore. Well Sha-24 in North Tarim Basin is taken as an example, and the gypsum-salt creeping pressure in this well is analyzed. The result shows that this model coincides with the real condition in the well.