An elastic self-positioning pre-dicing device and method, the device includes a V-shaped self-positioning device, a cutter and a separation device; the V-shaped self-positioning device includes first and second elastic conveying faces which form a V-shaped conveying space, and materials are kept in a vertical state when arriving at a bottom end between the two elastic conveying faces with the conveying of the faces; the cutter is arranged at the bottom end between the two faces to cut the materials in half along a long axis; and the separation device is arranged at the lower part of the cutter and configured to convey the materials cut in half to next stage respectively. This overcomes the defects of low efficiency in manual dicing of seed potatoes and waste of seed potatoes. The half-cut seed potatoes will be conveyed to next intelligent dice identification station to ensure high utilization of seed potato production.