Abstract: In this paper,based on the work of Wang and Zhu (1989),the influence of environmental flow on the interactions between binary vortices (IBBV) is simulated and studied by using a non-divergent barotropic model. The experimental result demonstrates that the environmental flow has significant influence on the IBBV. For the two vortices,the environmental flow intensifies their mutual cyclonic rotation to make them tend to meet,or causes the effect to be counteracted or seperates them to less close distance. It depends on the relative positions of the binary vortices and their spatial association with the environmental flow.