Tower type seed grading processing system with high grading precision and low crushing rate

The utility model belongs to the technical field of seed processing, and particularly relates to a tower type seed grading processing system with high grading precision and low crushing rate, which comprises a primary cylinder screen grader, a secondary cylinder screen grader, an indent cylinder grader and a grading bin, the first-stage drum screen grader is connected with the two second-stage drum screen graders through a first-stage grain feeding pipe, a first-stage three-way valve and a first-stage grain discharging pipe; through tower-type series-parallel connection arrangement of the first-stage cylinder screen classifier, the second-stage cylinder screen classifier and the indent cylinder classifier, two to eight stages of classification of seeds are achieved, the types of seed classification are widened, the precision and efficiency of seed classification are improved, the commodity quality of the seeds is effectively improved, the equipment arrangement mode is compact in structure, the occupied area i