A V-shaped bending device was established to evaluate the effects of temperature and bending fillet radius on springback behavior of 2219-W aluminum alloy at cryogenic temperatures. The cryogenic springback mechanism was elucidated through mechanical analyses and numerical simulations. The results indicated that the springback angle at cryogenic temperatures was greater than that at room temperature. The springback angle increased further as the temperature returned to ambient conditions, attributed to the combined effects of the “dual enhancement effect” and thermal expansion. Notably, a critical fillet radius made the springback angle zero for 90° V-shaped bending. The critical fillet radius at cryogenic temperatures was smaller than that at room temperature, owing to the influence of temperature variations on the bending moment ratio between the forward bending section at the fillet and the reverse bending section of the straight arm.