In this work, based on the propagation properties of Lamb wave, an approach is proposed to detect damage location in composite material. Two piezoelectric knots are utilized in this approach, each knot includes three piezoelectric transducers. Damage scattering signals are collected using piezoelectric knots. In this method, the difference of time and displacement between each transducer is obtained using the propagation speed of Lamb wave. Considering the geometrical position of piezoelectric transducers, the spreading direction of scattering signals is computed with a direction algorithm, in which the arrival time of the wave packet to each transducer is utilized. This direction is the one that the lamb wave occurs scattering from the damage position. By this way, each piezoelectric knot can detect one spreading direction from the damage location. Therefore, the damage location is determined with the intersection of these identified directions. Moreover, the validation of the damage location detection method is given in this work. The fundamental theory of cross correlation is investigated, and the cross-correlation algorithm is used to extract the damage scattering signal. Experimental tests have been performed on carbon fiber reinforced resin matrix composite plates to validate the detection method. The damage location is obtained and compared with the experimental results. It reaches a good agreement, and this scenario indicates the robustness of this method to detect the damage location.