A solvent‐free induced self‐assembly technology for the synthesis of nitrogen‐doped ordered mesoporous polymers (N‐OMPs) is developed, which is realized by mixing polymer precursors with block copolymer templates, curing at 140–180 °C, and calcination to remove the templates. This synthetic strategy represents a significant advancement in the preparation of functional porous polymers through a fast and scalable yet environmentally friendly route, since no solvents or catalysts are used. The synthesized N‐OMPs and their derived catalysts are found to exhibit competitive CO 2 capacities (0.67–0.91 mmol g −1 at 25 °C and 0.15 bar), extraordinary CO 2 /N 2 selectivities (98–205 at 25 °C), and excellent activities for catalyzing conversion of CO 2 into cyclic carbonate (conversion >95% at 100 °C and 1.2 MPa for 1.5 h). The solvent‐free technology developed in this work can also be extended to the synthesis of N‐OMP/SiO 2 nanocomposites, mesoporous SiO 2 , crystalline mesoporous TiO 2 , and TiPO, demonstrating its wide applicability in porous material synthesis.