Phenolated pyridine-based porous ionic polymers (Py-PiP OH) was synthesized in one step through Friedel–Crafts alkylation reaction. The structure, morphology and thermal stability of PY-PIP OH were characterized by FTIR, XPS, SEM, XRD and TG. The pore parameters and CO₂ adsorption properties of Py-PiP OH were analyzed by N₂ and CO₂ adsorption-desorption measurements, respectively. The results showed that the Py-PiP OH framework had abundant phenolic hydroxyl, pyridinium ionic liquid units and microporous structures. The specific surface area (S_BET) of Py-PiP OH is 155.4 m₂^{/g, and the adsorption capacity of CO}₂ is 37.1 cm₃^/g at 273 K and 0.1 MPa. Py-PiP OH showed excellent catalytic performance in the cycloaddition reaction of CO₂ with a 4-(chloromethyl)-1,3-dioxolan-2-one yield of 96.3% at 100 ℃, 1.0 MPa and without any cocatalyst for 12 h. When simulated exhaust gas (15% CO₂+85% N₂, volume ratio) was used as raw material, the yield of 4-(chloromethyl)-1,3-dioxolan-2-one could still reach 90.3% at 100 °C and 3.0 MPa for 24 h. The effects of temperature, pressure and other reaction conditions on the cycloaddition of epichlorohydrin and CO₂ were investigated. Moreover, Py-PiP OH presented good substrate expansibility and could be reused for 5 times without significant loss of catalytic activity and selectivity.