A multi-leaf collimator includes a driving component, a controller and n leaf-group layers, where n is an integer greater than or equal to 2, wherein each leaf-group layer includes one group of leaves or two opposing groups of leaves, each group of leaves includes a plurality of leaves, each of the leaves includes a front end surface and a rear end surface which are opposite to each other, and each of the leaves is movable so that the front end surfaces of the leaves in the multiple leaf-group layers form a variable-shaped region that allows beams to pass through； and the rear end surface of the leaf is connected to the driving component, and the controller is configured to control the driving component to drive the leaf to move.
