The invention relates to an electroplastic incremental forming device and an electroplastic incremental forming method for plates. The device comprises a five-axis numerical control forming machine tool, a six-axis parallel robot machining system, a plate forming clamp, a high energy pulse power supply, an infrared thermometer, and a compressed air cooling system embedded in the machine tool, wherein an upper forming pressing head is arranged at the tail end of a spindle of the five-axis numerical control forming machine tool; the six-axis parallel robot machining system is arranged on a working table of the machine tool; the top of the six-axis parallel robot machining system is provided with a lower forming pressing head; the plate forming clamp is fixed on the working table of the machine tool; positive and negative poles of the high energy pulse power supply are connected with the upper forming pressing head and the lower forming pressing head through high current-carrying conductors respectively so as to form a current loop among the high energy pulse power supply, the upper forming pressing head, the lower forming pressing head and the plates; a camera of the infrared thermometer is aligned with a central area of each plate; and the compressed air cooling system is aligned with a forming area of each plate. Compared with the prior art, the invention has the advantages of high efficiency, energy conservation, high machining precision, high surface quality and the like.