Abstract: The causes of frame column through defect in a project were analyzed, and partial structural model was set up for numerical analysis under different load conditions, so as to determine the influence on inner forces of joining structural member caused by the frame column through defect.On this basis, the reliability of the structure was assessed to work out a strengthening scheme using carbon fiber composite, whose strengthening effect was very good.The analytic results indicate that the greater change would occur in the inner forces of joining structural member when frame column has through defect, and the structure could not meet requirement of earthquake proofing construction and potential safety hazard existed.Frame column has through defect should be strengthened in time, and need take effective measures should be taken to assure structure safety in work progress, at the same time, strengthening effect should be detected for assessing whether the strengthened structure meet the design requirement.