This preheating machine is used for preheating magnesium ingots and automatically conveying preheated magnesium ingots to the furnace. The preheating machine adopts a worm gear The worm gear reducer drives the lead screw to lift upwards. After detecting its position, the magnesium ingot is sent to preheating by the ingot pushing cylinder Preheating is carried out in the area, and the preheated magnesium ingots are sent to the ingot feeding mechanism through a pushing cylinder, and then smoothly fed into the crucible. This preheating has high preheating efficiency, long service life of heating elements, small footprint, and can be adjusted according to the size of the model A minimum of 120 magnesium ingots can be placed for secondary use.