The 3000m drilling project undertaken by the Sixth Geological and Mineral Exploration Institute of Shandong Province in Shuiwangzhuang, Zhaoyuan is the deepest hole in Zhaoping Fault Zone with the completion depth at 3000.58m, operation period of 232 days, and a record in the drilling efficiency for the similar holes in small diameter wireline drilling. In this paper, the project schedule management is taken as the research topic, and the various aspects of the drilling process are deeply analyzed in the preliminary design. WBS was used to break down the work to find out the main aspects that affect the progress of the project with the import buffer set up. The key chain technology was used to optimize the drilling progress and achieved good results. The key chain technology enables project managers to have a dynamic and real-time control of the entire project, which is of great significance to deep hole drilling and large-scale drilling works.