The invention discloses a prestressed duct mud jacking technology adopting a post-tensioning method. The prestressed duct mud jacking technology comprises the following steps that a special joint is mounted, a special plug is mounted, a special valve is mounted, mud jacking is conducted, pressure maintaining is conducted, the special valve is removed and cleaned, and an iron sheet cover and the plug are removed. According to the prestressed duct mud jacking technology, the compactness and plumpness of cement paste can be ensured, the engineering quality is effectively improved, and the problemof low compactness of mud jacking is eliminated, meanwhile, the time can further be saved, and the construction period is shortened.