The present invention features a long-term controlled release formulation of the nalbuphine pro-soft drug, Sebacoyl dinalbuphine ester, in combination with commonly used pharmaceutical excipient biodegradable polymer PLGA. Said formulation was selected from the following groups of pharmaceutical formulations including such as: tablets, capsules, soft capsules, granules, suspensions, microspheres, oral implants, implantable injections and others. Said long-term controlled release formulation significantly improved the dosage and frequency for administering nalbuphine to once per half month or few months, compared to four to six times per day in the traditional way, which is one of the major features and effects of the present invention. The major improvement of this invention can be achieved by confirmation of the pharmacokinetic profiles and the duration time of efficacy level of drug through in vivo experiments, subsequently improves the dosage and frequency of the traditionally used nalbuphine injections.