Abstract: The three-section large-bore wellbore structure of deep coal and gas horizontal wells in the Zimi Block of the eastern Ordos Basin suffers from problems such as low drilling efficiency and long downhole treatment cycles for issues like lost circulation and well collapse, making it difficult to meet the needs of low-cost and high-efficiency coal and gas development. To address this, by analyzing regional geological characteristics, drilling engineering challenges, and the problems existing in the three-section large-bore wellbore structure, an innovative "guide pipe + deep surface" two-section small-bore "slimmed-down" wellbore structure was designed. Key technologies such as the selection of efficient speed-up tools for "one-trip drilling," optimization of drilling hydraulic parameters, three-dimensional horizontal well trajectory control, strong inhibition and strong plugging low filtration drilling fluid system, and optimization of segmented measures were studied, resulting in the development of horizontal well drilling technology for deep coal and gas in the Zimi Block. In field trials, this technology was applied to the drilling of four wells, with an average well depth of 3902 m and an average mechanical drilling rate of 13.24 m/h. The single-well fault handling cycle was reduced from 225.00 h to 32.75 h, the drilling cycle was shortened from 82.54 days to 27.12 days. Drilling costs decreased by 34.53%, achieving the technical goal of "separate treatment of collapse and leakage", and effectively solving the problems of low drilling efficiency and frequent downhole complications in deep coal and gas development. The horizontal well drilling technology for deep coal and gas in the Zimi Block provides new technical support for the low-cost, large-scale, and efficient development of deep coal and gas in the eastern Ordos Basin.