Abstract: The purity of Seeds is the most important quality index of Sorghum seed testing. The evaluation of Seeds grade is on the basis of the test. The seed purity level of Sorghum Yield and quality were analyzed.The results of test have direct and significant influence, therefore, this paper analyzes the causes of affecting the sorghum seeds purity drop ,and then we try to finding out the countermeasures.These work in sorghum seed production plays an important role in the future,which Brings us benefits in seeds production with high purity, good quality.