Abstract: An imaging method,which combines the MUSIC (Multiple Signal Classification) algorithm and linear sensor array,was proposed and used for monitoring the composite structure damage.This method utilized the array signal processing method based on MUSIC algorithm,which performed the eigenvalue decomposition of the covariance matrix of array signal and then calculated the spatial spectrum by direction scanning to realize damage imaging.The method has an advantage of arranging the linear sensor array easily.The experiment on the aircraft oil tank,which was made of carbon fibers with a variable thickness,was established.Experimental results show that the proposed method can realize damage imaging on aircraft composite structures accurately,and the damage localization error is less than 2 cm.