To study the gas flow behavior in parallel cyclones, two kinds of parallel cyclones, consisting of 2 and 4 identical cell cyclones (model PV with a barrel diameter of 300 mm) respectively, were numerically simulated with Fluent. The cell cyclones were axial-symmetrically arranged and shared an inlet pipe, an upper gas chamber and a dust hopper. The gas medium was atmospheric air with the inlet velocity of 15~30 m/s. The total flow fields were compared between cell cyclones and a single cyclone. The results show that the difference of flowrate between cell cyclones does not exceed 0.35% for 2 cyclones and 0.28% for 4 cyclones both in parallel, and the maximum difference of corresponding pressure drop is not more than 0.79% and 0.43%, which means the flow is evenly distributed in all cell cyclones. Cross flow does not appear in the common dust hopper. For 4 cyclones in parallel, the stability index of vortex flow in each cell cyclone is below half of that in a single cyclone. Theoretical analysis on axial-symmetrically arranged point vortices indicates that the higher stability is ascribed to the inherent property of vortex system, which effectively weakens the sway of precessing vortex core in cell cyclones. There are favorable effects on particle separation in axial-symmetrically arranged parallel cyclones.