A strategy for overcoming strength-ductility tradeoff of RAFM steel is realized through the introduction of numerous nanoparticles homogeneously dispersed in ultrafine-coarsen (bimodal grained) grained ODS steel matrix. Optimized the interface of Y2O3 oxide by in-suit grown carbide coatings, significantly improving the dispersion state to achieve dense uniform dispersion of nanoparticles, thus obtaining ODS-Y2O3@C sample with extraordinary strength (~1222 MPa) and ductility (~16.8%). Notably, the densely dispersed Y2O3 nano-particles, which have a semi-coherent relationship with the Fe matrix, leading to high strength (~ 356 MPa). This study provides a new way to fabricate dispersion-strengthened RAFM steel with high strength and good ductility, which have potential application in the field of future fusion reactor.