Four-axis clamp capable of finishing turnover in one-step

The invention discloses a four-axis clamp capable of finishing turnover in one-step. The four-axis clamp comprises a baseplate, positioning pins, compressing devices and mistake-proofing pins. The compressing devices include side compressing devices, a left compressing device, a right compressing device and two middle compressing devices. Three side compressing devices are equidistantly at each of the upper edge and the lower edge of the baseplate. The left compressing device and the right compressing device are respectively arranged in the middle of each of the left edge and the right edge of the baseplate. The two middle compressing devices are arranged in the middle of the baseplate. The left compressing device, the right compressing device and the middle compressing devices are arranged on a same straight line and equidistantly distributed. One positioning pin is arranged at the position, corresponding to each of the side compressing devices, of the baseplate, and one mistake-proofing pin is arranged on the left of each of the side compressing devices at the upper edge of the baseplate. The four-axis clamp capable of finishing turnover in one-step is simple in structure, convenient to use, and capable of improving producing efficiency by mounting three workpieces at one time, avoiding mounting mistake and improving processing quality.