During the urban planning, there exists a need for geological disaster investigation. Drilling is the most common way to survey the geological environment of the research area. However, how to determine the locations of the boreholes reasonably is an important problem.We have adopted the Delaunay Refinement technique to determine the location of boreholes. Delaunay Refinement technique can generate relatively well-distributed triangular mesh by inserting some new points at the circumcenter of triangles. In the engineering practice, ZhengDong new district neededto carry out a geological disaster investigation. The government required the distance between any two boreholes not to exceed 1.5 kilometers to guaranteeaccuracy. The existing 40 boreholes data, collected from the constructed buildings,along with the border of ZhengDong new district as the constrained conditions, the locations of new boreholes can be determined the by Delaunay Refinement. The locations of new inserting points just are what we needed. Using this method, the optimal layout of boreholes can be achieved. Thus, this method produces not only a rational result, but also reduces the cost.