To locate the impact source on a composite material structure, an energy eigenvector and correlation interpolation (EECI) method is proposed based on a multi-fiber Bragg grating (FBG) sensor array. The fundamental frequency interference is eliminated by the wavelet transformation. The signal energy feature vector is extracted by the wavelet packet transformation. A two-dimensional correlation matrix is obtained by analyzing the correlation between impact response signals and signals in the reference database. The linear interpolation is then applied to accurately predict the impact location. The EECI method is verified on a carbon fiber composite plate with an effective test size of 400  ×  400 (mm). The experimental result shows that the mean absolute error is 16.18 mm and the mean relative error (MRE) is 4.04%. The influence of the FBG sensor arrays and the quantity on the localization accuracy is also discussed to optimize the layout of the localization system. It shows that the MRE is [25.32%, 44.50%] for a single FBG sensor array, [17.19%, 42.63%] for two FBG sensor arrays, [15.63%, 22.47%] for three FBG sensor arrays, which shows the advantages of multi-FBG sensor arrays.