Under the general tendency of current social economic transition,city reconstruction is in full swing.The voice of both dismantling constructing and effective utilization,integration transformation exists.In Germany where industrialization has been highly developed,a saying is often cited that reasonable usage is half maintenance.As to the industrial plants whose production functions have been canceled,finding a new suitable one for it is the key to provoking their potential vitality.It was made an in-depth analysis of the renovation and reconstruction of Tianjin Hongqiao Carpet Factory,and presented several suggestions on the function replacement of old industry architectures.