Expansion: The teaching assistant client stores the fragmented resources needed by teachers' teaching in the cloud through cloud storage, and the resources needed by each functional module are provided by the cloud, and the resources are classified according to the chapters and directories of the teaching materials. Before preparing lessons, teachers can choose the resources they need to use in the corresponding chapter directory in the cloud, or they can open the cloud to directly call and edit resources during the course. This way of cloud storage makes teachers do not need to copy files even if they change computers, and they can successfully complete the preparation for teaching by logging in to the teaching assistant with different computers. "Textbook Resources" mainly provides users with their own editing and processing resources collected in the cloud, and can view and collect resources shared by other users and fine resources. All resources are associated with the textbook chapter catalogue for easy search and use. "Subject tools" include lesson preparation tools closely related to disciplines, and different disciplines include different tools, such as providing a dictionary of sea words for Chinese and English disciplines, providing formula editing for mathematics disciplines, providing formula editing and experimental instruments for physics disciplines, and providing formula editing, experimental instruments and atomic structure diagrams for chemistry disciplines.