The invention relates to the technical field of mechanical transmission, in particular to a wedge-shaped disc-type adjustable-speed magnetic coupling. The shaft coupling of the present invention includes a driving disc device, a driven disc device and a speed regulating mechanism. Among them, both the driving and driven discs adopt wedge-shaped disc structure, the purpose of which is to simultaneously change the facing area and the size of the air gap between the permanent magnet and the conductor, quickly adjust the magnetic flux of the air gap magnetic field, and control the output speed and speed better and faster. The size of the torque. At the same time, the axial movement of the driving rack (21) is controlled by the speed regulating mechanism, so that the square bearing base (18) can also move accordingly, and then the lower rack (14) and the right side are pushed by the two-way thrust ball bearing (19). The wedge-shaped driven disk moves, and now the motion is passed to the upper rack (10) by the gear (12), so that the upper and lower racks drive the corresponding left and right wedge-shaped discs to move toward or away from each other. That is to say, the distance between the master and slave discs can be changed at any time during the operation of the coupling, thereby changing the torque and speed of the driven shaft, and achieving the purpose of stepless speed regulation.