A subsection girder anchor structure of a concrete girder comprises a girder, an otic placode, and a high strength friction grip bolt. The structure looks like a box with wing plats in appearance. A subsection girder passes through lateral plates of the concrete girder, is fixed by the high strength friction grip bolt and is connected with a cable stayed bridge and a suspension cable by the otic placode. The bending moment generated by prestressing balance suspension cable and the shearing force caused by the high strength bolt resisting suspension cable can effectively control long term flexivtiy of a concrete continuous rigid frame. The structure has low cost, convenient and simple assemble, and wide applicability, is safe and reliable, and is widely applied in a long term flexivtiy control proposal of a complete long span continuous rigid frame.