Recently, I have been conducting experiments on Lamb wave excitation efficiency analysis in composite materials, but the wide target frequency band leads to serious multi-mode aliasing of Lamb wave. Moreover, due to the limited size of the object to be tested, the boundary reflected waves of different modes, the modal converted waves and the direct waves of each mode are aliased together and cannot be distinguished. I searched for a lot of papers, but still didn't find a suitable solution. I would appreciate it if anyone else had this problem and would like to share a solution.