A facile and continuous synthesis method of polyimide hollow nanoparticles has been developed by microemulsion reprecipitation method using a microfluidic system within a short reaction time (10 s). The mean particle size and the coefficient of variation were 314 nm and 0.22, respectively. We also successfully demonstrated that the polyimide hollow nanoparticles can be used as a nanocontainer as well as nanoreactor by retracting a chemical dye such as Rhodamine 6G.