Down-the-hole (DTH) hammer with casing while drilling (CWD) is a technology that has been proven to be able to alleviate many of the problems faced by complex formations. However, the drill bit is suffered from rapid wear, low drilling efficiency, and high energy consumption due to the unreasonable tooth arrangement and impact energy selection in drilling process, which affect the application effect of this technology. ABAQUS software was used for numerical simulation of rock breaking behavior under impact load with the single, three, and five teeth arrangement drill bit respectively, to improve the application effect and solve the aforementioned technical problems. Based on the calculated parameters of tooth arrangement, we designed a novel drill bit for hard rocks and provided a theoretical basis for the tooth arrangement of largediameter drill bits.