The invention discloses a core making machine, and relates to the technical field of metal casting. The core making machine comprises a rack and a sand shooting unit, the rack comprises four guiding rod stand columns and further comprises a first fixed plate, a second fixed plate, a first movable plate and a second movable plate which are arranged on the guiding rod stand columns, a lower core boxis fixed to the second fixed plate, an upper core box is fixed to the first movable plate, and a plate is fixed to the centers of the outer sides of the first fixed plate and the second fixed plate,guide rails are fixed to the two sides of the plate, the middle of the plate is fixedly provided with a translation cylinder, the telescopic end of the translation cylinder is fixedly provided with asand blocking plate, and the two sides of the sand blocking plate are located in the guide rails. The core making machine reduces the difficulty of manual sand blocking, improves work efficiency, andreduces the scrap rate.