As the airtight web of civil aircraft is located in the airtight area and mainly bears the pressure load inside the cabin, fatigue failure and crack may occur in the web of civil aircraft under cyclic loading. In order to study the fatigue performance of the airtight web, a method of crack prediction was proposed and verified by the fatigue test. According to the force transmission characteristics and test results of the airtight web structure, the typical fatigue parts and the severe cyclic loading conditions of the airtight web were determined. The web grid of typical fatigue parts (including connecting fasteners) was selected, and the hexahedron element was taken as the smallest element to establish a fine finite element model.The simulation analysis was carried out, and the crack location and mechanism were obtained, which were consistent with the actual situation. Based on the detailed fatigue rating(DFR) and the fatigue checklist, the fatigue life of the airtight web was analyzed. And the crack growth life of the airtight web was calculated by NASGRO software. The fatigue test cycle number of crack initiation and propagation to the critical crack length were close to the real flights when discovering the crack, and the theoretical analysis was conservative.