The slicing technology of hard-brittle materials by endless diamond wire saw has the advantages of higher moving speed of wire saw, better slicing quality, and thin kerf. According to the strength of wire saw, the cutting force and the random vibration of wire saw, the slicing parameters are optimized. As single crystal silicon is sliced, the constant feed force is less than ION, the maximum pretension is 30N, and the highest moving speed of wire saw is 24m/s. But because the restrict of machine precision, the highest slicing speed is 16m/s.