A method of using finite state machine to design human-machine interface based on liquid crystal is proposed by analyzing the special character of state transition of finite state machine. The paper discusses the process of human-machine interface design in detail by using C language and taking menus transition for example. Menus transition is achieved by using SPLC501C liquid crystal and display driver for menus transition is given. Practice has proved that this method is feasible

easy to extend the number of menu and can avoid the emergence of non illegal states

and the menu transition is very fast

stable and reliable.