The invention relates to an automobile U-shaped part local copious cooling rolling preparing method suitable for aluminum, aluminum alloys, copper and copper alloys. A metal coiled material is machined to be at the length, width and thickness required by products, a metal plate strip is obtained, a corner bending deformation zone of the metal plate strip is marked, a marked part is subjected to local copious cooling treatment through cooling nitrogen, the cooling temperature is -190 DEG C to -50 DEG C, a continuous rolling mill with a hole type is started, high frequency ultrasonic wave vibration is adopted on a lower hole type roller, a workpiece obtained after local copious cooling treatment is machined with the continuous rolling mill with the hole type under ultrasonic wave assistance,and a U-shaped part without rebounding and corner crack defects is prepared.