The invention discloses a crane and a suspension arm thereof. The suspension arm comprises a basic arm (4) and a rotating arm (3), wherein the first end of the basic arm (4) is connected to the main body (15) of the crane; the first end of rotating arm (3) can be rotationally connected with the second end of the basic arm (4); the rotating arm (3) can rotate in the rotating plane, in which the amplitude variation plane of the basic arm (4) is intersected with the rotating arm (3). In the crane disclosed by the invention, since the rotating arm is arranged additionally, that the whole revolving platform rotates is not required, to achieve lateral operation of the crane, all that is needed is to rotate the rotating arm. Therefore, the stability against overturning of the crane is improved, and the side overturning of the crane can be prevented effectively.