The utility model relates to a hydraulic pressure clamp, which is characterized in that a clamping head main body is U-shaped and two sidewalls of the U shape are inclined inward; a hydraulic cylinder is arranged in the opening at the back of the clamping head main body; a synchronization plate is fixed on the mandrel of the hydraulic cylinder; two pieces of inclined wedge blocks and the synchronization plate are of the mode of slide connection; the inclined planes of the two inclined wedge blocks and the two sidewalls of the clamping head main body are of the mode of slide connection and the two right-angle planes are arranged in mutual parallel; two clamping plates are respectively connected with the right-angle planes of the two inclined wedge blocks. The mechanical clamp is utilized to clamp the single-leaf strip steel and realize tension rolling. Besides, the design of the utility model is a more-haul-more-tight structure, which is able to guarantee the tension realization of the pulling force device fore and after the rolling mill to the strip steel and avoid the occurrence of sudden down loading.