The frame is entirely welded with steel plates, and treated to relive stress by tempering. Hydraulic drive, return of knife beam is smooth and prompt by accumulator or nitrogen cylinder. The portable and prompt adjusment of the blades gap and the value of gap are indicated by digital, convenient and fast. Equipped with lighting-alignment, so as to align when shearing. The stroke of knife beam can be adjusted in stepless mode. Protection fence to ensure the operation safety. The display devices of the backgauge value and the shearing times are on the front of the machine.