Seed stone bench to the main use of seed grain and gravel and other differences in the density or specific gravity of cleaning small seed after sorting for sorting. Work surface for the rectangular structure, the storage hopper is located in the middle of a rectangular work surface, feed speed control by adjusting the hopper door opening to achieve; machine working process, the feed material in the table position at the bottom of blast vibration and role of rapid stratification, the heavier impurities along the length of the table to the table high-end mobile, and lighter seed grain along the length of the table moves to the low-end to achieve the seeds and stones, soil particles and other separation. Work table (length) vertical angle, frequency table, the bottom of the fan flow, etc. are adjustable to meet a variety of (small seed) the same dimensions, the density of different seed sorting requirements.