Abstract: A short section concrete of a corner column of a frame prism column on 1th floor is unqualified，the strength of concrete is relatively low，therefore，by comparing the reinforcement schemes of concrete，the method of stage replacing concrete is selected． Because the column has a large part of the structual load，to ensure the structure and the construction operations safety，it is measured the strain of the support structure and the replaced structure and the deformation of unloading points during unloading process，with which the internal forces，deformation，residual deformation of the structure at replaced concrete position can be reflected accurately，which can provides reliable basis for unloading． It is also described the test results of construction and the replacement of the reinforcement effect．Finally，advices of design and construction are also put forward for this sort of project．