The invention relates to a back shore device for air pipe and angle steel rivet driving connection and a construction method of the back shore device. The back shore device for air pipe and angle steel rivet driving connection comprises a lining structure, a hook assembly and an operation rod. The lining structure is attached to the inner side of an air pipe and corresponds to angle steel. The hook assembly is rotationally connected to the lining structure and arranged on a second folded edge of the angle steel in a hung manner, and a connecting supporting point is formed at the joint of the hook assembly and the lining structure. The operation rod is connected with the lining structure, and the operation rod and the lining structure are arranged on the angle steel through the hook assembly in a hung manner. Downward pressure is applied to the operation rod, and therefore the lining structure is attached to the inner side of the air pipe through the connecting supporting point, and then the lining structure can support the air pipe and a first folded edge of the angle steel. By means of the back shore device, an air pipe and angle steel rivet driving position is prevented from being sunken downwards and deforming, and the problem that rivet driving cannot be supported through connecting piece driving to cause deviation is solved.