In daily life, the decimal system is used more, but in computer system, all the data exist in binary mode. In the process of Arduino teaching, number system conversion is the basic knowledge, and mastering binary notation is of great help for students to understand the program. But this part of knowledge is rather boring with no good teaching method, and teachers just write on the blackboard. Therefore, I adopted LilyPad as the main control board and designed this teaching aid. First, it can be used as a binary clock. Secondly, it can be used to demonstrate the binary calculating method. Thirdly, the hardware and software design of the work can be easily transferred to Arduino, which is a very interesting and practical course resource for maker teaching.