As a new long-span space system, the prestressed arch-supported reticulate shell structure performs the advantages of reticulated shell and prestressed structure. The construction process, large span/depth ratio and small critical load of long-span space structure, can lead to obvious stress excess of tensile steel, especially when prestressed arches are used in truss arch and reticulated shell combined structure. However, no research was conducted on how the residual stress in the steel affects the structure stability. Thus, the dynamic behavior of some actual structure is simulated numerically through modal analysis by ANSYS in this paper. The results show that, for prestressed arch-supported reticulate shell structure, the vibration frequency increases with the whole stiffness, and the prestress can improve obviously the buckling ultimate load. There is great difference in vibration modes for different structure styles. This kind of hybrid structure conducts good whole performance, and may be used widely in the near future.