With the deepened advancement of educational informatization, especially the introducing of the rain classroom, blended teaching has been endowed with richer connotation, and the teaching reform in colleges and universities has been further promoted. Blended teaching mode based on rain classroom integrates network information technology into traditional teaching process, which can realize the dual-channel teaching of "synchronous" and "asynchronous". The application of rain classroom in undergraduate course teaching of science and engineering has remarkable effect in solving such problems as tedious classroom, large amount of notes, heavy task of correcting homework, formality of assessment, difficulty of quantification, and contradictions between less teaching hours and more content of courses, more students in class and lack of interaction between teachers and students. In view of the problems existing in practice, such as excessive reliance on the network and smart phones and other equipment, the mismatch between teachers' extra energy input and teaching-hour subsidy, it is recommended to improve from technical and institutional guarantees to truly promote education reform and innovation.