The invention discloses an S-shaped arm. The S-shaped arm comprises an arm body; the arm body is formed by series connection of multiple connecting rods; the adjacent connecting rods are movably connected through rotating joints; each rotating joint comprises a pair of upper and lower bases and a cross-axle universal joint, and circles of first through holes surrounding first and second universal joint forks are correspondingly formed in the upper and lower bases; multiple positioning holes connected with the bases are formed in the upper and lower end surfaces of the connecting rods; an included angle formed by the two universal joint forks located on the upper and lower end surfaces of each connecting rod is (90+alpha) degrees, alpha is an acute angle, and the size of alpha can be adjusted according to the positioning holes; two pivots of each cross-axle universal joint sequentially penetrates through the corresponding first through holes in the upper and lower bases of the rotating joint below the cross-axle universal joint through four pull cables to be connected with a corresponding driving unit, and the driving unit pulls the pull cables to control the cross-axle universal joint to rotate, so that multi-dimensional movement of the S-shaped arm is controlled, and the high-flexibility operation ability is realized.