The invention discloses a method for installing a steel
cofferdam by the aid of a
pier supporting frame. The method comprises that a lifting frame and a guide frame are installed on a
pier, the steel
cofferdam is divided into a plurality of steel
cofferdam sections according to actual conditions, and each of the steel cofferdam sections is divided into a plurality of steel cofferdam units with chamfer angles. During construction, the lifting frame which is located at the top of the
pier or on one side of the pier and is used for lifting the steel cofferdam is installed firstly, the guide frame which is located on one side of the pier and can be used for guiding and positioning the
underwater steel cofferdam is installed, finally, steel cofferdam units are lifted horizontally and then adjusted to be vertical, and the steel cofferdam having a self-balancing capability can be formed through lifting and
assembly of sections and units by the aid of the lifting frame and the guide frame in such a sequence that upstream steel cofferdam units and downstream steel cofferdam units are installed and then steel cofferdam units in the middle are installed. The method can effectively solve the problems of
assembly, positioning and sinking of the steel cofferdam in a narrow and small space on the condition that no large lifting device is provided, and the method has the advantages of being good in adaptability, simple in structure, convenient to manufacture, good in
operability, safe, reliable, good in economical efficiency, good in application prospect and the like.