Method for installing A-shaped frame of heavy crane

The invention relates to the technical field of ship construction, in particular to a heavy crane A-shaped frame mounting method, which comprises the following steps: firstly, assembling an A-shaped frame on the ground or a deck, hinging the upper ends of a first support frame and a second support frame, and connecting a temporary support structure to the middle of the first support frame and the middle of the second support frame; then a lifting hook of a crane is connected to a hinged shaft of the first supporting frame and the second supporting frame, and the A-shaped frame is lifted to the position above the rotary chassis through the crane; then the position of the A-shaped frame is moved through a crane, and the lower end of one of the first supporting frame and the second supporting frame is connected to the rotary chassis; and finally, the temporary supporting structure is dismantled, and the lower end of the other one of the first supporting frame and the second supporting frame is connected to the r