High-performance and energy-saving microwave (MW)-assisted catalysts are of great significance for MW-assisted treatments of wastewater. Herein, a novel nitrogen-doped reduced graphene oxide aerogel with supported nanoscale zero-valent iron (nZVI@N-rGOA) was successfully synthesized and used in the MW-assisted removal of imidacloprid (IMI) from wastewater. The resulting nZVI@N-rGOA had an open pomegranate-like multicompartment structure consisting of wrinkled flaky reticular N-rGOA walls and embedded nZVI particles, and the nZVI@N-rGOA/MW system rapidly eliminated nearly 100% of the IMI in a 10 mg/L solution within 2 min. The highly efficient MW-assisted catalytic degradation of IMI resulted from synergistic effects, including the nZVI active centres, pyridinic N sites and open pomegranate-like multicompartment structures, which facilitated MW harvesting, mass transfer of the reactants and generation of heat, electrons, holes and •OH radicals. Accordingly, the localized surface plasmon resonance and electron transfer processes enabled catalytic oxidations/reductions, respectively. This work provides a novel paradigm for designing MW-assisted catalysts for wastewater treatment.