Abstract: During reforming the mill building of RC bent frame, it is solved effectively the problems and the contradiction between the production and construction by the following techniques: the scheme of cutting column with beam supported; according to the features of the project, using root pile to strengthen the foundation; using cap beam to reinforce column base; steel plate is also used to strengthen corbel and column flange; and using the feature of I-section column to cut web and support the column by steel joist.