A novel crosslinked polymer with a benzyl(triphenyl)phosphonium ionic liquid moiety was synthesized from triphenylphosphine and p-xylylene dichloride. The bulky IL molecules were inlaid in the polymeric framework, which avoided pore blocking and IL moiety release. The polymer had a high BET surface area and accessible active sites. The polymer was applied to catalyze the aza-Michael additions and gave average yields over 95.0% in several minutes. The polymer had several advantages such as high BET surface area, high activity and high stability, which hold great potential for green chemical processes.