With the deep drilling project of M24 mining area in Chengde, analysis was made on the application effect of selection of drilling parameters. In deep hole drilling, drilling pressure should be selected by considering the drilling diameter; hardness, strength, abrasiveness, integrity of rock. Within a certain range, the ROP of diamond bit is proportional to the rotary speed; the selection of flushing fluid should be based on the bit type and size, matrix properties, drilling depth, rock abrasiveness and integrity; the appropriate enlargement of the outside diameter of diamond bit can effectively avoid the hazards of high pressure pump; down-hole drill rod conditions can be determined by observing the changing value of current in current instruction sheet of main motor. Current changes reflect the changes of rotary torque of the drill.