Abstract: To minimize the multi-modes and dispersion phenomena and to enhance the signal strength of Lamb wave Electromagnetic Acoustic Transducer (EMAT), this paper proposes a multi-objective optimization method for Lamb wave EMAT based on the combination of the “two-intersection-points” method and “zero-slope” criterion with the orthogonal test method. The “two-intersection-points” method and the “zero-slope” criterion can effectively minimize the influence of multi-modes and the dispersion phenomena of Lamb waves respectively; and the orthogonal test method is able to enhance the signal strength of Lamb wave signals. Nine prime parameters of a Lamb wave EMAT which is commonly used for the inspection of aluminum plates are optimized based on the proposed multi-objective optimization method. Experiments show that after optimization, not only the multi-modes and the dispersion phenomena are notably depressed, but also the signal strength is greatly enhanced, which significantly improves the practicability of the transducers.