The traditional load calibration constraint method affects the measurement of wing root load on the wing-body integrated structure with landing gear layout. In this paper, a wing load measurement method suitable for this structure is proposed. Firstly, the impact of the change in main landing gear load during ground load calibration on the strain bridge response of the wing root load measurement section is analyzed. An active constraint method is proposed to simulate the actual loading state of the aircraft wing in the air. Secondly, comparative test of wing load calibration is conducted using the active constraint and the traditional landing gear constraint methods. By analyzing the test data, the flight load equations for the two constraint methods are established. The ground checking error of both methods is within 3%, which meets the general requirement for engineering errors. Finally, the symmetrical pull-up maneuver flight test state is selected to verify the effectiveness of the wing load measurement method for the wing-body integrated structure with landing gear layout, and the reason for the large error in load measurement using the traditional landing gear constraint method is also given.