Drilling pile drilling construction method of bead-type karst area

The invention discloses a drilling pile drilling construction method of a bead-type karst area, wherein a drilling pile penetrates through an underground river karst cave from top to bottom. The method includes the steps of (1) measuring and sampling, (2) lowering and fixing a steel casing, and (3) drilling, wherein a percussion drill is used, drilling is carried out from top to bottom through the lowered steel casing until the percussion drill reaches a designed depth, and in the drilling process, the wall is protected through slurry; in the drilling process, when the percussion drill drills the underground river karst cave from top to bottom, the underground river karst cave is firstly processed, and then the percussion drill is used for drilling downwards; when the underground river karst cave is processed, the process is as follows: drilling of an inner protection casing installation hole, lowering of an inner protection casing, continuous drilling and plugging of a water source. The method is simple in step, reasonable in design, low in investment cost, convenient to achieve and good in construction effect, the drilling construction process of a drilling pile penetrating through the underground river karst cave can be easily, conveniently and quickly completed, cost is low and quality is high.