The Longmaxi Formation in the Changning Block of the Sichuan Basin has a large reservoir thickness and is a high-quality shale for the main shale gas bearing target layer. However, problems such as high rock strength, high drillability level, and large horizontal drilling length in the Longmaxi Formation have led to rapid failure of the drill bit and slow ROP (Rate of Penetration). Research has found that almost all PDC drill bits used in this formation are foreign products, and the drill bits have failure due to core and external cone cutter impact. Therefore, in order to achieve the localization of Longmaxi formation drill bits and the goal of ‘one trip drilling’, personalized design and application of PDC drill bits are carried out. The rock mechanics property parameters of Changning Longmaxi Shale were obtained by obtaining rock samples on the spot and conducting rock mechanics property experiments. To solve the problem of external cone failure of foreign drill bits, the first generation of axe shaped PDC drill bits targeting the Longmaxi Formation were designed and developed. The average drilling speed of the first generation PDC drill bit is 7.4m/h, which exceeds most PDC drill bits abroad, but is still lower than the highest average drilling speed of foreign drill bits. In order to further improve the bit's invasion ability and directional stability, the profile shape and cutter arrangement of the first generation PDC bit were further optimized, and drilling simulation was conducted. After optimization, the bit's invasion ability and directional stability increased. After optimization, the drill bit footage was 2005m, with an average drilling speed of 10.77 m/h, which was 45% higher than before optimization, far exceeding the highest drilling speed abroad, and achieving the goal of ‘ne trip drilling’ for long horizontal sections. The successful application of this drill bit provides in-depth understanding and experience for increasing drilling speed in the Longmaxi Formation in Changning.