The invention discloses a ground mobile carrying tool and a steering system thereof. The steering system comprises a steering part, a steering shaft, an input shaft, a left push rod and a right push rod, wherein one end of the steering shaft is coaxially and fixedly connected with the steering part; the input shaft is arranged vertically, and the upper end of the input shaft is rotatably connected with the steering shaft through a universal joint; the right end of the left push rod is connected with the left end of the right push rod through an intermediate piece, and the intermediate piece is fixedly connected with each of the left push rod and the right push rod and can drive the left push rod and the right push rod to get close to each other or separate from each other relatively; the lower end of the input shaft is connected with the left push rod or the right push rod, and when the input shaft rotates, the left push rod or the right push rod is driven to move in the transverse direction of the ground mobile carrying tool; when the left push rod moves in the transverse direction of the ground mobile carrying tool, a left output shaft can be driven to rotate; when the right push rod moves in the transverse direction of the ground mobile carrying tool, a right output shaft can be driven to rotate. Through the structural design of the steering system, a large angle steering function of the ground mobile carrying tool can be realized.