The theme of the 9th National College Students' Mechanical Innovation Design Competition (2020) is "Smart Home, Happy Family", which mainly includes machinery for helping the elderly and smart home machinery. No matter which type you choose, the mechanical structure should be novel and not heavy, the materials should be suitable and the transmission should be reliable. Think from the user's point of view (ergonomic). Give full consideration to various problems that may occur during use, and do corresponding protective treatment (to meet safety). After satisfying the usability, safety and novelty, the humanized intelligent control system is implanted into mechanical devices to realize the Internet of Things, which can be monitored and operated remotely. Don't tie your thoughts. When you have a good idea, you should realize it one by one and improve it constantly. After sorting out the main ideas, you can invite experienced teachers and students to participate in the evaluation. In the evaluation process, record the questions raised by everyone and seriously consider them. You shouldn't listen to other people's advice. You should keep your "initial heart", and you can't help but listen to good opinions. Good mechanical design is obtained after continuous improvement. I hope it helps you.