Lattice sandwich structures have drawn considerable attention in engineering applications owing to their exceptional specific strength, specific stiffness, and outstanding impact resistance. Regarding structural dynamic performance, current research predominantly concentrates on global vibration responses while overlooking the influence of local vibration characteristics of lattice trusses on dynamic behavior as fundamental aspects for nondestructive evaluation techniques. This investigation systematically examined the local vibration properties and damage detection methods for lattice sandwich structures. Firstly, combined numerical simulations and experimental measurements were conducted to analyze the effects of lattice trusses on guided wave propagation characteristics. Signal processing through Fourier analysis and wavelet transform revealed distinct energy concentrations at specific frequency peaks. Furthermore, by correlating the guided wave signals with local resonance modes of lattice unit cells, we demonstrated that these characteristic frequency peaks were intrinsically determined by the vibrational modal frequencies of lattice trusses, particularly their axial compression-tension vibration modes. Based on these findings, an innovative damage identification methodology is developed that utilizes the frequency peak shifts in wave signals for structural integrity assessment. The proposed approach is numerically validated, with results confirming its effectiveness in both damage detection and localization for lattice truss structures.