Everything has advantages and disadvantages, and online teaching is no exception. First, if students' self-control ability is not strong and parental supervision is not in place, many students may "euphemistically" take online classes on the ground, but they are actually playing a trick called "changing cages for birds", which is actually playing games, delaying learning and wasting time. Second, online teaching cannot solve the problem of two-way communication between students and teachers in targeted learning. Due to screen obstacles and limited interaction between the two sides, students can only complete the planned courses in a daze, and the important and difficult points of knowledge points cannot be discussed on the spot. They are mostly in a state of little knowledge, their learning efficiency is not high, they are easy to get tired, and their eyesight is affected. Thirdly, due to the limitation of teaching time and cyberspace, teachers cannot effectively guide students to complete classroom exercises and homework, and students' memory, consolidation and digestion of knowledge will be affected.