According to various of the technical difficulties such as low drilling efficiency in hard rock and short service life of diamond drilling bit, analysis was made on the inherent links between blade-extruding of hot-pressing diamond and rock abrasiveness. The matrix and properties were considered to be important factors, so starting with the research on matrix and properties of hot-pressing diamond drilling bit, hot-pressing iron-based impregnated diamond drilling bit was developed. Drilling in hard and compact rocks, the efficiency increased from about 0.5 m/h to about 1.17 m/h, and the service life was extended from 10 m/each to 21.31 m/each. It was proved that iron-based alloy is a new matrix material of diamond drilling bit and hot-pressing iron-based impregnated diamond drilling bit is a new type of diamond drilling bit.