By considering the cutting and feed force, tension and band camber, a simplified force analysis mode was set up to investigate the failure pattern of bandsaw blade crooked cutting. The stress distribution and its variation trends of bandsaw blade were obtained through numerical simulation. The result shows that the stress in the tooth side is more likely to be pushed for the situation with larger workpiece, cutting force, insufficient tension and band width. Thus, the bandsaw blade is bent near the teeth tip, and then crooked cutting happens. Under the same failure standard and cutting parameters, when the tension of band increases from 130 MPa to 190 MPa, the cutting pieces were added by 177%. Changing the 27 mm bandsaw blade to 34 mm leads to nearly 50% more cutting pieces, but it is dropped by 83% when increasing the width of the workpiece from 80 mm to 240 mm.