An exoskeleton joint self-locking mechanism, comprising a first base having a first compartment; a rotating outward expanding locking member disposed in the first compartment, the rotating outward expanding locking member comprising a first rotating frame and a second rotating frame, and outer sides of the first rotating frame and the second rotating frame having a first friction surface; and one end of the first rotating frame being pivoted with one end of the second rotating frame, and other ends of the first rotating frame and the second rotating frame being relatively free ends; a second base having a second compartment; the second base being rotationally mounted on the first base, and an inner wall of the second compartment enclosing the rotating outward expanding locking member and forming a second friction surface matching the first friction surface; a locking driving member capable of applying/canceling a force pushing away from a free end of the first rotating frame and a free end of the second rotating frame, to make the first friction surface close contact to lock/unlock the second friction surface; further, the free end of the first rotating frame and/or the free end of the second rotating frame being provided with a stress slope surface, the locking driving member being provided with a telescopic locking portion, the telescopic locking portion having a force applying slope surface, and the force applying slope surface applying force to the stress slope surface along with the telescopic locking portion, wherein the first base includes a chute, the locking driving member includes a driving motor, and the telescopic locking portion is a locking slider disposed in the chute; and a locking measuring mechanism comprising: a synchronous shaft rotating synchronously with a driving shaft of the driving motor; a signal transmitter and a signal receiver disposed opposite to each other at intervals; a measuring turntable, a rotation center of the measuring turntable being connected to the synchronous shaft, and an edge spacing of the measuring turntable being cyclically provided with a signal marked area and a signal unmasked area; and the measuring turntable rotating with the synchronous shaft to circularly block/switch on a signal connection between the signal transmitter and the signal receiver. a first base having a first compartment; a rotating outward expanding locking member disposed in the first compartment, the rotating outward expanding locking member comprising a first rotating frame and a second rotating frame, and outer sides of the first rotating frame and the second rotating frame having a first friction surface; and one end of the first rotating frame being pivoted with one end of the second rotating frame, and other ends of the first rotating frame and the second rotating frame being relatively free ends; a second base having a second compartment; the second base being rotationally mounted on the first base, and an inner wall of the second compartment enclosing the rotating outward expanding locking member and forming a second friction surface matching the first friction surface; a locking driving member capable of applying/canceling a force pushing away from a free end of the first rotating frame and a free end of the second rotating frame, to make the first friction surface close contact to lock/unlock the second friction surface; further, the free end of the first rotating frame and/or the free end of the second rotating frame being provided with a stress slope surface, the locking driving member being provided with a telescopic locking portion, the telescopic locking portion having a force applying slope surface, and the force applying slope surface applying force to the stress slope surface along with the telescopic locking portion, wherein the first base includes a chute, the locking driving member includes a driving motor, and the telescopic locking portion is a locking slider disposed in the chute; and a locking measuring mechanism comprising: a synchronous shaft rotating synchronously with a driving shaft of the driving motor; a signal transmitter and a signal receiver disposed opposite to each other at intervals; a measuring turntable, a rotation center of the measuring turntable being connected to the synchronous shaft, and an edge spacing of the measuring turntable being cyclically provided with a signal marked area and a signal unmasked area; and the measuring turntable rotating with the synchronous shaft to circularly block/switch on a signal connection between the signal transmitter and the signal receiver. a synchronous shaft rotating synchronously with a driving shaft of the driving motor; a signal transmitter and a signal receiver disposed opposite to each other at intervals; a measuring turntable, a rotation center of the measuring turntable being connected to the synchronous shaft, and an edge spacing of the measuring turntable being cyclically provided with a signal marked area and a signal unmasked area; and the measuring turntable rotating with the synchronous shaft to circularly block/switch on a signal connection between the signal transmitter and the signal receiver.