The invention discloses a wind tunnel test data correction method for a near-space high-aspect ratio flexible spacecraft. The wind tunnel test data correction method comprises a basic state data correction of wind tunnel test, a horizontal tail installation angle adjustment and a data correction of wind tunnel test pilot. The wind tunnel test data correction method combines the prior test conditions for wind tunnel tests in China and completes the correction of the wind tunnel test data of rigid body shape by means of aeroelastic and fluid mechanics analysis. The wind tunnel test data correction method can provide accurate aerodynamic data for near-space high-aspect ratio flexible spacecraft control rate design and flight simulation and ensure that the aircraft can stably flight under the condition of large deformation near the space.