Abstract: A new wood-biomass grinder had been developed and designed to solve the problem of higher power consumption and lower productivity during the wood raw material was shattered. The cutter-disc was designed based on the principle of cutter and shatter, the test of different diameters branch was completed after this grinder was made. The results showed, for the branch of diameter was less than 10 cm, the grinder work well, the productivity was 2.1 m3/h and the material size met the requirement of forming. The power consumption was increased with the branch diameter increase, for the branch of diameter was between from 10 cm to 15 cm, the power consumption was 15.7 kw·h/m3, and the grinder was close to normal work. But for the branch of diameter was more than 15 cm, the power consumption was increased by 55.8% and the grinder can’t work well.