The invention discloses a reference
repair method for a large-size mold. The four reference blocks are externally attached to a first
station machining area and a second
station machining area of the die respectively; on the first
machine tool, alignment is conducted based on the original datum plane and the original datum hole of the to-be-repaired mold; after alignment, the middle of the two original datum holes in the
machining area of the first
station serves as the original point of a machining coordinate
system, conversion datum holes are machined in the two datum blocks in the machining area of the second station, the top faces of the four datum blocks are milled into conversion datum faces, and the coordinate positions of the conversion datum holes are recorded; the to-be-repaired mold is transferred to a second
machine tool to level and convert the datum plane; the original datum hole of the first station machining area is aligned and centered to serve as the original point of a machining coordinate
system for machining of the first station machining area; after machining is completed, the mold is rotated by 180 degrees; leveling a conversion
reference surface; and after leveling, the coordinate position of the conversion datum hole is input into a second
machine tool, and a machining coordinate
system of a second machining area of the station is constructed. According to the invention, the
reference alignment is more accurate, and the safety of mold repair is improved.