In the Yan’an National Terrestrial Shale Gas Demonstration Zone, there are problems such as low mechanical drilling speed, long drilling time, which directly affects exploration and development of terrestrial shale gas at low-cost, high-efficiency. Increasing the drilling speed is important means to shorten the drilling time and reduce the drilling cost, and it is also a direct indicator of optimum and fast drilling. This paper analyzes the rock mechanical characteristics of the terrestrial shale formation, and carries out theoretical research on three aspects: optimizing the drill bit, optimizing the drilling mechanical parameters and hydraulic parameters so as to enhance the adaptability of the drill bit to the formation, and improve the wellbore cleaning ability and the drilling speed. As a result, the key drilling technology suitable for the development of terrestrial shale gas horizontal wells has been developed with 3 horizontal wells successfully completed in the demonstration area. The drilling time was shortened by 11 days, and the horizontal drilling rate increased by 120.08%. It has achieved optimum and fast drilling of horizontal wells for terrestrial shale gas and is worthy of promotion.