Joint locking mechanism and multi-joint surgical instrument arm

The invention provides a joint locking mechanism and a multi-joint surgical instrument arm, and relates to the field of medical instruments.The joint locking mechanism comprises a locking cylinder, a locking piece and a piston column, the locking piece is provided with a plurality of first positioning holes and second positioning holes which are annularly distributed, and the first positioning holes and the second positioning holes are arranged in a staggered mode in the circumferential direction; the piston column reciprocates under the pressure effect of fluid in the locking cylinder so that the joint locking mechanism can be switched between the locking state and the unlocking state, and when the joint locking mechanism is in the locking state, the piston column is inserted into the first positioning hole or the second positioning hole so that the first swing arm and the second swing arm can be kept relatively fixed. Compared with the prior art, the joint locking mechanism provided by the invention is simp