A motion control system for a mechanical arm, a terminal end of the mechanical arm is adapted to carry an effector, and the motion control system comprises a controller provided with a graphical user interface, a first input device and a second input device, characterized in that: the graphical user interface is configured to receive a first control command from the first input device, the first control command is configured to control the mechanical arm to move according to a first movement mode, and the first movement mode is that the mechanical arm moves from a current position to a target position under a driving of its own power; the graphical user interface is further configured to receive a second control command from the first input device or the second input device, the second control command is configured to control the mechanical arm to enter a second movement mode, and the second movement mode is that the mechanical arm is configured so that its terminal end can be translated in a predetermined plane and rotated about a normal line of the plane under a driving of an external force; the second input device is configured to input a third control command, and the third control command is configured to control the effector to perform a predetermined action, the predetermined action is that an oscillating saw carried by the effector starts to oscillate according to a predetermined frequency and amplitude; wherein the first input device and the second input device are separated from each other or are provided to be separable from each other, and the first input device and the second input device are arranged within control ranges of different operators respectively, and the effector is configured to be unable to execute the third control command when the mechanical arm executes the first control command. the graphical user interface is configured to receive a first control command from the first input device, the first control command is configured to control the mechanical arm to move according to a first movement mode, and the first movement mode is that the mechanical arm moves from a current position to a target position under a driving of its own power; the graphical user interface is further configured to receive a second control command from the first input device or the second input device, the second control command is configured to control the mechanical arm to enter a second movement mode, and the second movement mode is that the mechanical arm is configured so that its terminal end can be translated in a predetermined plane and rotated about a normal line of the plane under a driving of an external force; the second input device is configured to input a third control command, and the third control command is configured to control the effector to perform a predetermined action, the predetermined action is that an oscillating saw carried by the effector starts to oscillate according to a predetermined frequency and amplitude; wherein the first input device and the second input device are separated from each other or are provided to be separable from each other, and the first input device and the second input device are arranged within control ranges of different operators respectively, and the effector is configured to be unable to execute the third control command when the mechanical arm executes the first control command.