There are hard wheat and soft wheat according to horny content. Horny rate of soft wheat is less than 70%, wet gluten content is about 19% ~ 25%. Horny rate of hard wheat is more than 70%, wet gluten content is about 29% ~ 35%. Hard wheat is with higher horny content and much compact endosperm than soft wheat, so it will get a larger extrusion pressure and shear force in milling processing . The main difference of average anti-stress is mainly reflected on whether endosperm become into a powder readily,that is to say,roller clearance of reduction system is difference. The difference of shear force is mainly reflected on the different roller parameters of Break system. in head grinding stage. The power consumption of soft wheat to hard wheat is about 80% under same process parameters. Epidermis and endosperm of hard wheat and soft wheat are with different water absorption speed and capacity,so there will be different expansion after absorbing water , it is resulting in the separation situation between epidermis and endosperm of hard wheat and s oft wheat . It is easier to scrap hard wheat epidermis , but its epidermis is fragile because high brittleness.