This is a Gobang game software developed using Visual C#, which realizes the human-machine battle, and the stand-alone version of Human-human battle. Regardless of the game mode, user can regret the game, redo, save the game and read the game during the chess process. The manmachine battle mode uses an algorithm that only considers one step, so that the computer has the most basic artificial intelligence, but it needs to be further improved. In this paper, firstly, it gives a specific introduction to the functionality and UI of the game, then reflects on objectoriented programming and changes, and gives the class diagram of the entire program and the timing diagram of some moments. Finally, the pattern used in the design and development process is summarized, including the structure of the program, the structure of the class, and the operating mode of the pattern.