Hydraulic internal expansion workpiece surface aligning clamp

The utility model relates to the technical field of workpiece machining, and discloses a hydraulic internal expansion workpiece surface aligning clamp which comprises a hydraulic cylinder, the output end of the hydraulic cylinder is fixedly connected with a movable plate, the bottom of the hydraulic cylinder is fixedly connected with a fixed plate, and the bottom of the fixed plate is fixedly connected with a fixed rod. Sliding rods penetrate through and are slidably connected to the two sides of the outer wall of the fixed rod, first connecting shafts are fixedly connected to the front ends of the sliding rods, second connecting shafts are fixedly connected to the front ends of the moving plates, rotating rods penetrate through and are rotatably connected to the outer walls of the second connecting shafts, and clamping blocks are arranged on the adjacent sides of the two sliding rods; and a driving assembly is arranged in the sliding rod. According to the utility model, the clamping plate, the first connecti