This system can meet the requirements of low temperature, dust free and adjustment of granularity. The main measures are that when pulverizing materials, supplying the cold air at the same time, and control the speed of feeding by an adjustable, speed control screw feeder, thus, to make sure that the temperature of crushed material is lower than set value (eg: 35℃) in process of pulverizing. Different granularity can be obtained by adjusting speed of rotary knife and replacing different sieve mesh. The powder flows in an airtight system in the whole process, which is collected by separating gas and solid, and then the dust-free exhaust is exhaled.