The fatigue test-bed is also called pulse test-bed and alternating pressure test-bed, which simulates the pressure-bearing parts in the actual working condition (including the medium flowing through the pressure tube, the pulse pressure, etc.) , and carries on the alternating pressure pulse test to the pressure-bearing parts, check whether the bearing parts can complete the cycle number in the standard under the condition of high and low pressure, check the fatigue life and the form of fatigue failure.