The teaching evaluation of students is a management regulation usually used by universities. The validity of the teaching evaluation, in other words, the quality of the teaching evaluation got the high concern of teachers, students and teaching administrators. In the paper, semantic technology is used for sentiment mining of students' messages waiting, and sentiment lexicon based on CNKI is formed, and the polarity weights of the words in sentiment lexicon are different. 3 GWS is used to distinguish Chinese...