Multiple pylons are the most important suspending equipment for bomb in one plane. A detailed research was made. At first, the composition and principle were discussed. Then on the base of functional requirements, the pulse generator of multiple pylons was designed with the computer, weapon control panel, USB data acquisition system and joystick. It could vividly simulate the operating process and dropping effect. It would also make the shackle be opened by cool air instead of combustion gas. The result shows that the hardware-in-the-loop system is more reliable.