In order to design a robot well, the exterior design and the internal system design should be well coordinated. The two are inseparable. First of all, you should combine his functions to design his appearance. It's simple. You can't design the sweeping robot to look like a food delivery robot. Secondly, the internal structure and system, that is, the sensory system and the executive system of the robot, represent all the principles of the output of the executive system with sets. The mechanism of assembly is discussed through this system, so that the robot can feel the changes of the external environment and make changes. Another concept is control principle, which is produced by the interaction between structure and environment. The structure is uncontrolled and only controlled when the environment is still. Not all structures can produce effective control, so robot programming is also very important.