The invention relates to the technical field of crank forming dies, and relates to a crank roll forging blank forming die. The crank roll forging blank forming die comprises a traditional four-pass roll forging die, a roll forging upper die and a roll forging lower die are arranged between a third pass and a fourth pass, wherein the roll forging upper die and the roll forging lower die are used for removing blank flash; the roll forging upper die and the roll forging lower die are arranged between the third pass and the fourth pass, a blank is subjected to roll forging in sequence through theroll forging upper die and the roll forging lower die, wherein the hole-shaped sections of the roll forging upper die and the roll forging lower die are oval, moreover, the length of the long axis ofthe oval is a = R + x, the length of the short shaft is b = R - y, wherein R is the design radius of a forge piece, the value range of x ranges from 4 mm to 6 mm, and the value range of y ranges from1 mm to 3 mm. According to the crank roll forging blank forming die, the blank can be prevented from generating the flash through the arrangement so that the blank can be placed into a circular cross-section die cavity to smoothly finish final forging, and a qualified product is produced.