A magnesium alloy cast-rolling unit, including: a main body; a fluid supplier; an electric pushrod; a linkage mechanism; a horizontal platform; a screw; dovetail guide rails; and a bottom plate. The main body includes a base, a spring cylinder, a hydraulic adjustment cylinder, a connection portion, and a cast-rolling unit body. The connection portion includes an arc-shaped rail. The spring cylinder includes an actuation element. The actuation element includes a piston rod and a pressure strip. The piston rod includes an external thread at one end; and the pressure strip includes an internal thread corresponding to the external thread. The fluid supplier includes a head box, a corrugated pipe, a compression spring assembly including a gland cover, a connection pipe including a convex pipe joint and a concave pipe joint, a flat plate including a groove, a smelting furnace, and a horizontal operation platform.