Provided in the present invention is a pharmaceutic osmotic pump preparation comprising a tablet core, wherein the tablet core contains drugs (or pharmaceutically active ingredients) and materials forming a chamber structure and a coating film coating the tablet core where a drug release hole is set wherein when the pharmaceutic osmotic pump preparation releases drugs in water or an aqueous medium, the materials forming the chamber structure lead to the formation of a superfine chamber structure in the coating film, and the total volume of the superfine chamber structure Vb gradually increases over the releasing time, but the releasing rate R (or release amount A) of the pharmaceutically active ingredients is proportional to Vb. The osmotic pump preparation of the present invention is suitable for water-soluble drugs and water-insoluble drugs, and especially is suitable for the controlled release of low solubility drugs or pH dependent drugs.
