In this article, an optical fiber sensing array system based on semiconductor ring laser is proposed for impact location monitoring on aluminum plate. A fiber Fabry-Perot etalon is used to demodulate the signal of fiber Bragg grating sensor (FBG). The strain applied to the FBG is encoded as the wavelength shift of the reflected light of the FBG sensor. Then, it is converted into intensity modulation by the optic Fabry-Perot etalon with a FSR of 50 GHz. The optic F-P etalon can demodulate multiple FBG signals at the same time via wavelength division multiplexing. The optical fiber sensing array system is installed on an aluminum plate with a thickness of 1 mm. A 50 g small steel ball falls freely at a height of 20 cm and strikes the aluminum plate to generate acoustic emission signals. By using time-frequency wavelet analysis, the group velocity dispersion curve of Lamb wave is obtained from the measured transient response of the FBG sensor, and the coordinates of the impact point are determined according to the triangular positioning algorithm. Through the impact test, the average positioning accuracy error of the system and positioning algorithm is 30. 89 mm, which achieves good accuracy.