Orthogonal　catalysis　is　emerging　as　a　powerful　method　for　the　synthesis　of　block　copolymers.　By　employing　a　single　designed　dual-function　photoredox　phosphoric　acid　catalyst　(Photo-PA),　two　types　of　polymerizations　via　different　mechanisms,　photo-triggered　organocatalyzed　atom　transfer　radical　polymerization　and　acid-triggered　ring-opening　polymerization,　can　be　effectively　bridged,　discriminated　and　performed　simultaneously　in　one　pot.　This　orthogonal　system　also　features　metal-free　conditions,　visible　light　regulation,　the　use　of　a　single　catalyst,　as　well　as　good　compatibility　and　control,　allowing　the　synthesis　of　block　copolymers　with　the　desired　component　and　low　dispersity　in　a　one-pot　approach　and　controlled　manner.　©　2022　The　Royal　Society　of　Chemistry.