The invention provides a compound preparation of pioglitazone hydrochloride and metformin hydrochloride bilayer osmotic pump controlled release tablets. The compound preparation structurally comprises the following parts from inside to outside in sequence: a tablet core comprising a drug layer and a digestive layer, an insulation coating layer, a controlled release coating film with drug release holes, a rapid pioglitazone hydrochloride release layer and an unnecessary attractive coating. The invention also provides a preparation method of the compound preparation of pioglitazone hydrochloride and metformin hydrochloride bilayer osmotic pump controlled release tablets. The preparation method comprises the following steps of: (1) preparing the drug layer; (2) preparing the digestive layer; (3) tabletting the tablet core; (4) coating insulation coating layer; (5) coating the controlled release coating; (6) punching the coated tablet: (7) coating the rapid pioglitazone hydrochloride release layer; and (8) coating the attractive coating.