Abstract: 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.