S-shaped joint used for surgical robot, surgical instrument and endoscope

The invention provides an S-shaped joint used for a surgical robot. Plane torsion or spacial torsion is achieved through swing of a joint connection pair. Compared with an S-shaped joint in the prior art, the structural complexity is reduced. The invention further provides a surgical instrument and an endoscope which comprise the S-shaped joint. Accordingly, the tail end of the instrument or an imaging system can reach a desired position and gesture.