One of the challenges in water remediation is adsorbent designing, aiming at low cost and ultrafast contaminant adsorption. Herein, we developed a simple and scalable one-pot synthesis method to achieve a cost-effective anionic hypercrosslinked polymer ( AHCP-1 ) through the Friedel–Crafts reaction with sodium tetraphenylboron as the monomer. To the best of our knowledge, this is the first anionic hypercrosslinked polymer synthesized using the Friedel–Crafts reaction. Notably, AHCP-1 possessed a high specific surface area of 939 m 2 g −1 with a micro-/mesoporous structure. Owing to the high surface area, the abundant phenyl groups and the built-in ionic charges, AHCP-1 displayed ultrafast adsorption towards dyes and phenolic derivatives, and a high adsorption capacity of 229.89 mg g −1 for RhB and 540.5 mg g −1 for BPA. It is also found that the adsorption behavior is dependent on the pollutant concentration, the pH value, and the structure and charge states of the pollutant molecules.