A research for optical fiber distributed sensing technique based on optical frequency-domain reflectometry is conduct to realize the health monitoring for aircraft structure with high accuracy and high resolution. The principle of cross-correlation distributed sensing based on Rayleigh scattering spectrum is introduced, and the limitation factor of sensing gauge length in traditional cross-correlation method on spectral resolution is analyzed. A Fourier interpolation method is proposed to enhance the spectral resolution, and experiments are carried out to verify the spectral resolution. The experimental results show that continuous distributed sensing can be obtained with the proposed method when we use a 14.2 m single mode fiber with spectral resolution of 1.6 pm and sensing gauge length of 1 cm. The proposed method with high accuracy and high resolution is promising in short and medium health monitoring applications.