The account number of the cloud class is the student number. But bind the phone number. Cloud Classroom On any mobile device or PC, you can easily manage your own class, manage students, send notices, share resources, assign homework, organize discussion and answer questions, and conduct teaching interaction. Interactive teaching activities such as voting questionnaire, brainstorming, work sharing and time answering can be carried out in any ordinary classroom or immediately after class. Immediate feedback, immediate comments. All published course information, learning needs, courseware, micro-videos and other learning resources can be instantly transmitted to students' mobile devices, so that students' mobile devices will become learning tools from now on, not just socializing. With the blue ink intelligent three-dimensional teaching material, the tracking of each student's learning progress and the evaluation of learning effect can be realized. At the end of the semester, the teacher can get the evaluation report of each student's digital textbook. Based on the behavioral big data collected by real-time interactive feedback in the classroom, the personalized teaching suggestions for each teacher and personalized support for students are given by using the user portrait technology.