Asymmetric cell division (ACD) produces morphologically and behaviorally distinct cells and is the primary way to generate cell diversity. In the model bacterium Caulobacter crescentus, the polarization of distinct scaffold-signaling hubs at the swarmer and staked cell poles constitutes the basis of ACD. However, mechanisms involved in the formation of these hubs remain elusive. Here, we show that a swarmer-cell-pole scaffold, PodJ, forms biomolecular condensates both in vitro and in living cells via phase separation. The intrinsically disordered and coiled-coil 4-6 regions of PodJ mediate biomolecular condensate generation and its signaling protein recruitment. Moreover, a negative regulation of PodJ phase separation by the staked-cell-pole scaffold protein SpmX is revealed and SpmX disturbs PodJ subcellular accumulation and affects its recruitment ability. Together, by modulating the assembly and dynamics of scaffold-signaling hubs, phase separation may serves as a general biophysical mechanism that underlies the regulation of ACD in bacteria and other organisms.