In the paper, a modeling and simulation method of queue systems based on State flow is put forth. At first, the concepts of queue systems and State flow are introduced. Then, the analyzing procedure of establishing queue systems model based State flow is put forth according to finite state-machine theory and object-oriented programming concept. At the end, State flow is used to model and simulate the M/M/1/∞/∞/FIFO queue systems. The simulation result suggests that the model and simulation base on State flow can describe the statistics character of queue systems effectively, and it has the merits such as visualization, flow chart and hierarchy.