A high-efficiency and stable preparation system for high-strength fire-resistant magnesium boards, including a frame, a transmission device, a driving device, a demoulding device, a purging structure, a rolling device, and an unwinding device; the transmission device is arranged at the head end of the frame and The middle end; the driving device is correspondingly arranged at the bottom end of the transmission device, and the driving device includes a driving motor, a driving roller and a driving belt; the demoulding device is arranged on the top side of the frame, and is arranged on one side of the head-end transmission device; The structure is set on the top side of the frame and on one side of the demoulding device; the rolling device is set at the middle and end of the frame, and the rolling device includes a roller frame, a movable frame, a cover, an adjusting motor, and an adjusting wire. Rod, sliding rod, pressing roller and rolling motor; the number of unwinding devices is two, which are arranged end to end, and the unwinding device is arranged at the middle end of the frame. The release liquid of the invention has strong coating uniformity; the non-woven fabric layer has high-efficiency bonding, and the coverage uniformity is high; the rolling forming precision of the magnesium plate is high, and the thickness control degree is good.