According to actual drilling wells in Gucheng area, there are many technical difficulties in drilling "black quilt" strata, H2S, stuck drilling, well leakage, overflow, well collapse and formation pressure and temperature, which lead to long drilling cycle and high drilling cost in this block. Geological characteristics in this paper, according to the ancient city area, combined with the drilling purpose of well Gucheng 601 and well completion method, the comprehensive consideration of well bore such as formation pressure, will seal point, on the premise of ensuring safety and quality, optimize well structure of Well Gucheng601, according to the real drilling verified that the design is reasonable, for optimize well structure of Well Gucheng601 well bore structure design provides a new way of thinking.