Abstract: In order to solve the problem that grouting casing in coal seam affects coal mining, the technical method of sectional cutting of grouting casing in coal seam was adopted. Based on the research and design of casing cutting bit, three different cutting tools, that is, PDC cutting tool, hot-pressed diamond cutting tool and electroplated diamond cutting tool were selected in Zhaogu No. 1 Coal Mine where two sets of comparative cutting tests were carried out for 4.5 mm thick double-layer casing (casing specifications Φ108 mm and Φ127 mm). The experimental results show that all three kinds of cutting tools can achieve one-time cutting of double-layer casing, among which PDC cutting tools have higher cutting speed but lower life; hot-pressed diamond cutting tools and plated diamond cutting tools have higher life, and plated diamond cutting tools have higher cutting efficiency. Hardness has a great influence on the two kinds of diamond cutting tools.