Ground regional control technology has been widely used in coal seam floor karst confined water disaster control project. Ground regional control takes ground directional drilling technology as the core technology, and the key is the directional drilling design of curve trajectory, which is generally realized by use of  CAD design drawing software in practical work. But there is a lot of repetitive work in the design process. Based on the commonly used CAD software, this paper used LISP language for secondary development to solve many auxiliary design problems such as position query, curvature query, automatic drawing of drilling curve trajectory, automatic generation of curve trajectory profile and automatic acquisition of graphic data on any point on the curve. The study reduced the difficulty of regional control engineering design, reduced the cumbersome links of design and drawing work, shortened the design cycle, and improved work efficiency and design accuracy.