The utility model discloses a combination ingot mold for casting different flat ingots once, and belongs to the technical field of ingot molds for casting mold casting ingots. The combination ingot mold for casting the different flat ingots once is used to enable liquid steel in all ingot molds combined together for casting to simultaneously reach the required height. The technical scheme includes that the combination ingot mold for casting the different flat ingots once selects runner regulation bricks different in hole diameter according to weight difference values of different ingot shapes, achieves matching of the different ingot shapes and resistance loss of a runner system, guarantees that the liquid steel in all the ingot molds combined together for the casting can simultaneously reach the required height in required time of technology, breaks a traditional production mode of only casting the ingots identical in size and on the same disk in flat ingot mold casting, achieves simultaneous casting of the different flat ingots 200t in weight difference and 800mm in height difference on a bottom disk, and achieves a flexible production mode for the mold casting flat ingots. Furthermore, the combination ingot mold for casting the different flat ingots is simple in structure and convenient to use, solves puzzles in practical production, greatly improves casting efficiency of the ingot molds, and achieves prominent economic benefit.