During the wind tunnel testing, the balance will be subjected to aerodynamic dynamic loads for a long time, which may lead to fatigue failure of the balance. In severe cases, cracks or fractures may occur, which can not only cause damage to the balance, but also catastrophic situations such as test pieces falling off and being blown away along the surface of the wind tunnel. These unexpected situations often delay the entire development cycle of the aircraft. To reduce the risk of fatigue failure of the balance and ensure the safety of wind tunnel testing, the FL-9 wind tunnel pressurization test balance was taken as the research object. Combined with the finite element analysis results of the balance, high-risk stress nodes of the balance structure were extracted, and fatigue monitoring was carried out throughout the calibration and wind tunnel testing process of the balance. The test results indicate that the fatigue stress monitoring technology of the balance can ensure the safety of the balance. Based on this, the load range of each unit of the balance has been expanded by 1.5 to 2 times. The wind tunnel test results show that the balance still has sufficient safety margin to obtain a wider range of test data.