Green exploration is the embodiment of the new development concept in engineering investigation. As the most direct means of various engineering investigation methods, drilling is absolutely necessary; however, it also brings about many environmental problems. Through analysis of drilling features and possible environmental problems in engineering investigation, and in combination with actual drilling experiences and research, the drilling solutions for green engineering investigation were put forward and applied in SichuanTibet Railway investigation. The problems remained with current green engineering investigation are considered and concluded. It is advocated that the companies of investigation, design, construction and the relevant departments work together to establish a comprehensive green engineering investigation system.