Resin diamond wires with different SiC contents were prepared and the actual silicon wafer cutting experiments were carried out. The effect of SiC contents on the cutting ability of resin diamond wire was studied by recording the torque and cutting conditions during the cutting process. The results show that when the amount of SiC in resin liquid increases, the cutting ability of resin diamond wire increases gradually. But the cutting ability will be reduced when the content of SiC is over a certain level. In experiment, when the content of SiC in resin solution is 600 g/L, the cutting torque of resin diamond wire cutting silicon wafer is 96 N·m, and without cutting, while the cutting ability is the highest. At this time, the shore hardness of resin cured is 91 HD, SiC in resin layer are uniformly dispersed, and there are no defects such as pores.