Objective To prepare electro-spark deposited Ti( C, N) /Al₂O₃ coating on high-speed steel ( HSS) drills, and to investigate the cutting performance of the coating. Methods Ti( C, N) /Al₂O₃ composite coatings on high-speed steel ( HSS) drills were prepared by electrospark deposition technique using Ti( C, N) /Al₂O₃ as electrode material. The phase composition, morphology and hardness distribution of the coating were investigated, and the cutting performance tests of the HSS drill coated by Ti( C, N) /Al₂O₃ were also conducted. Results The microstructure of Ti( C, N) /Al₂O₃ coating was homogeneous with a thickness of 32 ~ 36 μm. The phase composition of the coating was mainly C0. 3 N0. 7Ti, Al₂O₃ , AlTi₃ , Fe₇W₆, Fe₄N, TiN and AlN. The average hardness of the coating was 2. 6 times higher than that of HSS. Conclusion Crack-free Ti( C, N) /Al₂O₃ coating could be prepared on HSS drill by electrospark deposition technique. The cutting performance of HSS drill with Ti( C, N) /Al₂O₃ coating was improved and the service life was prolonged.