The fatigue test of aviation structural components is one of the key links to verify the fatigue strength and durability of the structure. How to accurately detect and correct the peak value of test data with periodic and large data characteristics is directly related to the effectiveness of aviation structural life prediction and damage assessment. This article uses fiber Bragg grating strain sensors to monitor the health of a certain type of aviation structural component. Based on the data obtained during fatigue testing, the problem of data errors caused by spectral distortion is first solved. Subsequently, a method for detecting and correcting peak values of periodic fatigue test data is proposed, which achieves rapid detection and correction of peak and valley values of test data. This method is superior to traditional methods in terms of efficiency, accuracy, and robustness, and is suitable for key scenarios such as aircraft structural health monitoring and fatigue life assessment.