With the continuous development of information technology, the teaching method is not limited to offline teaching. Online teaching is on the rise, and more and more teachers use a blended teaching evaluation system that combines online and offline to carry out classroom teaching. However, during online teaching, teachers cannot remind students when students are not paying attention, resulting in low classroom quality. This paper applied artificial intelligence (AI) emotion recognition technology to the blended teaching evaluation index system. When students are studying in the course, the emotion recognition is carried out on the students; when the students are not concentrating, the students are reminded to ensure the quality of the students' learning. Through testing different classes it was found that: the application of AI emotion recognition technology to the blended teaching evaluation system can improve the quality of classrooms, and improve students' learning status and student performance. Student satisfaction had increased by 9.7%, and AI emotion recognition technology can optimize the evaluation index system of blended teaching.