Abstract: With the advantages of low cost and high drilling speed, the hot-pressed iron-rich based diamond bit has been deeply studied and applied in recent years. Compared to the same formula of the hot-pressed iron-rich matrix, the effect of the pre-alloyed CSB-2 addition and sintering temperature on the physical properties of diamond bit matrix were studied by compactness, microhardness, flexural strength and impact toughness tests. Results indicated that matrix performance of the added CSB-2 powder was better than that of the elemental mixed powders. With the increase of mass fraction of CSB-2, the compactness, microhardness, flexural strength and impact toughness of the matrix were increased by 7.68%, 27.99%, 94.43% and 312.82% respectively. At the same time, the pre-alloying of matrix formula could reduce the hot-pressing temperature. To obtain a good application performance, the optimum addition of CSB-2 should be higher than 30% and the preferred sintering temperature should range from 940℃ to 980℃.