The invention provides an U-shaped part roller shape cutting device and a cutting method thereof. The U-shaped part roller shape cutting device comprises an automatic loading car 1, an automatic unwinding machine 2, an automatic guide pressing head mechanism 3, an automatic plate leveling machine 4, a length measuring device 5, a servo tracking blanking machine 6, an automatic cold bend forming machine 7, a detecting switch 8 and a follow-up shearing machine 9; and the automatic loading car 1, the automatic unwinding machine 2, the automatic guide pressing head mechanism 3, the automatic plateleveling machine 4, the automatic cold bend forming machine 7 and the follow-up shearing machine 9 can be manually controlled or automatically controlled. The U-shaped part roller shape cutting method has the following advantages: (1) the production speed is high; and the whole shearing process adopts continuous blanking to achieve high production efficiency; (2) the problem of excessive deformation caused by curved surface cutting in the prior art is prevented; and twice cutting modes are both flat plate blanking, so that the deformation problem of workpieces after shearing is effectively reduced; and (3) the quality of produced products is stable.