A new class of yolk-shell structured precious metal@microporous polymer nanoparticles has been successfully developed. The polymer shells obtained by hypercrosslinking present well-developed permanent microporosity, controllable thickness, and good mechanical properties, and thus can be utilized to protect the precious metal yolks including Au and Ag nanoparticles from aggregation and inactivation. As a result, compared with unprotected Au nanoparticles, Au@microporous polymer nanoparticles not only present a higher utilization efficiency for the catalytic reduction of nitrobenzene and 4-nitrophenol, but also have a much longer cycling life. Ag@microporous polymer nanoparticles demonstrate highly efficient and long-lasting antibacterial properties, since the microporous shells enable the nanoparticles to release Ag+ from the Ag yolk to the solution in a long-term manner. We hope that our versatile yolk-shell nanoparticles will offer a new thought to solve the structural problems of yolk-shell materials, and thus provide a great opportunity for a spectrum of applications including medicine, catalysis, energy, adsorption and environment. (c) 2018 Elsevier Ltd. All rights reserved.