Abstract: A control method for the boundary reflection in the Lamb wave-based structural damage detection is presented. Firstly, a reasonable design of the STMR array form and a strategy for the signal receiving & sending are given based on the geometric symmetry of structure.Then, the signals from the symmetrical sensors are subtracted to eliminate the influence of the boundary reflection in the Lamb wave-based structural damage detection and to achieve an accurate identification of the structural damage near the border. Simulation results show that this method not only improves the accuracy of the structural damage detection but also effectively avoids the non-detection zone. This method does not involve complex numerical calculations and has good prospects for engineering applications.