Abstract: As a basic engineering experiment, chemical principle experiment is a bridge linking theory and engineering practice, which plays an important role in engineering teaching. However, the traditional teaching mode usually focuses on verification and operation experiments, which is insufficient to cultivate students’ innovation ability and engineering experiment ability. In order to meet the requirements of new engineering talents training, the combination of online and offline teaching mode is adopted to reform the chemical principal experiment. Blended teaching is a learning-centered experimental teaching mode. The teaching effect shows that online teaching improves the efficiency and quality of offline experimental teaching, and at the same time improves the dimension of students’ learning, they think and analyze problems from the perspective of thinking mode and working method.