Torsional beam type suspending rack is provided in the present invention. In the torsional beam type suspending rack making opening end face of towing arm and main shaft supporting plate butt welding,on the front end of the main shaft supporting plate (13) plate main body (13M), integrated connecting a front side bending flange (13F) extending along the back end external side of the towing arm (10) towards front and front end edge welding (W3) at the back end external side, and at the plate main body (13M) back end integrated connecting a rear side bending flange (13R) clamping and welding (4W) at the rear end edge of the towing arm (10). The main shaft substrate (14b) is overlapped and fixed (W2) on the external side of the plate main body (13M), and has four screw hole parts (Sfu, Sfd,Sru, Srd) at the front and back and un and down of the maid shaft axes separating the main shaft axes, the screw hole parts is used for combining the plate shape component (P) associated with the braking device and the bolt used for the main shaft substrate (14b), therefore, it can restrain effect of welding thermal strain, and can make the main shaft supporting plate thin-wall to realize light weight and lower cost.