A reconstituted grain product and manufacture method thereof. The reconstituted grain product includes a ground material having a plurality of raw whole grain. The method for manufacturing a reconstituted grain product includes providing a plurality of raw materials having whole grains, grinding the raw materials to afford a ground material with between 80.about.200 meshes, and subjecting the ground material to mixing, extrusion with water addition, forming and drying to yield a reconstituted grain product.