We herein develop a facile catalyst‐free method to prepare hyperbranched hydroxyl‐enriched aliphatic polycarbonate according to SCROP strategy. PEG‐attached multiarm hyperbranched copolymer HEHDO‐star‐mPEG was further designed. It was found that HEHDO‐star‐mPEG can self‐assemble into supramolecular multimolecular micelles in water. HEHDO‐star‐mPEG micelle showed excellent stability with respect to micellar size upon dilution, and displayed good cell‐biocompatibility. An anticancer drug of doxorubicin with hydrogen‐bonding functionality was incorporated into obtained micelles to establish a drug delivery system model. A high drug‐loading content as well as sustained release pattern for HEHDO‐star‐mPEG based delivery system was achieved.