The paper introduced the wall protection and leakage control technical measures for drilling in the complex formation of Haobugao mining area. According to the rock formation and the hole depth, wall protection and leakage control by casing, flushing fluid and cement sealing were adopted with good effect. Casing was safe and reliable, manual sodium soil low-solid mud has high inhibition function to downhole collapsing and block-falling, and cement has good sealing effect. Casing and cementing created favorable conditions for wire-line coring drilling with solid free drilling fluid and improved drilling efficiency.