Buffer leakage fault diagnosis method in test flight of undercarriage load

The invention, which belongs to the technical field of flight testing, provides a buffer leakage fault diagnosis method in the test flight of an undercarriage load. On the basis of recorded data of anundercarriage load calibration test and an airplane flight test, a load of flight of the undercarriage and a buffer oil damping force are calculated; the undercarriage load is projected to a centralaxis direction of the undercarriage support column and the buffer oil damping force is subtracted, so that a buffer aeroelastic force is obtained; a buffer stroke-buffer aeroelastic force curve is drawn and is compared with a static pressure curve; and according to the differences between the two curves, whether the undercarriage buffer has an air leakage problem is determined and the leakage timeis determined, and a buffer stroke and a load in the leakage state are recorded. Therefore, a problem of lack of a method for diagnosing the leakage fault occurrence time of the undercarriage bufferin the flight process of the