5XZ series gravity separator applicable to a variety of grains (such as: wheat, corn, rice, sunflower seed, barley, beans, sorghum and vegetable seeds, etc.) . It can select grain from mildew grain, worm-eaten grain, smut disease grain, bad grain, germinate grain, shell grain, and also other impurity which the weight is difference with good grains. After seed through selecting, the weigh of per thousand, clean rate, tidiness rate are all improved evident. If the grain had been done pre-cleaning and grading before gravity selecting, the gravity separator will be better separation efficiency.