Iridium‐on‐phosphorus‐doped porous organic polymers (POP−Ir) were developed by anchoring simple iridium onto the skeleton of porous organic polymers through coordination bonds. This POP−Ir catalyst, which was thoroughly characterized by means of EDS, SEM, TEM, XRD, XPS, and FT‐IR, revealed excellent catalytic activity for the reaction of diphenyl phosphinamide with benzyl alcohols through borrowing hydrogen strategy and acceptorless dehydrogenation with wide functional group tolerance. Moreover, this POP−Ir catalyst could be simply recovered and reused for at least five times without a significant loss of activity, and revealed considerable application prospects. The mechanism was investigated to further understand this POP−Ir catalytic system and transformations. Overall, the POP−Ir catalytic system has shown high activity and reusability in the borrowing hydrogen reaction between diphenyl phosphinamides and benzyl alcohols.