Selectivity and efficiency are always the most difficult challenges for adsorption technology, especially for the removal of trace amounts of antibiotics from an aqueous system. We employed the strong electrostatic interaction to enhance the binding energy between antibiotics of sulfadimethoxine (SDM) and adsorbents by designing an imidazolium-based porous ionic polymer (namely, TPFC-MIM PIP). TPFC-MIM boasted an ultrafast removal rate; 96.4% SDM was removed just within 1 min, with the adsorption rate constant (k = 1.69 g mg(-1) min(-1)) an order of magnitude higher than the reported values of state-of-the-art materials. TPFC-MIM also exhibited the highest capacity (394 mg g(-1)), excellent selectivity in the presence of equivalent fulvic acid, hundredfold-concentrated SO42- and NO3-, and also high removal efficiencies (>91%) in a very broad pH range of 2.0-11.