Abstract: A new straw grinder which could make 1 000 kg of 1mm powder in 1 hour by a creatively designed vibrating screen to satisfy the demand of scale and fine grinding of straw. Vibrating screen with amplitude parallel to rotor axial had been developed and designed. ANSYS software was used to analyze spindle static, vibration mode, and hummer static analysis in different load. And ADAMS software was used for dynamic balance analysis of the rotor tools. The performance test of the prototype showed that the grinder production rate of was 1 155 kg/h, power consumption 33.4 kWh/t; crushed particle with less than 1.2 mm was accounted for 98% of the sample quality, and with less than 0.9 mm accounted for 86%; vibration intensity of the rotor was level B in accordance with ISO-2372. And the performance of the straw grinder satisfied the requirement of design.