Abstract: Based on MAA Dah-You's general theory of the microperforated absorber, three layers microperforated structure absorption coefficient was calculated. By genetic algorithm parameters of the structure are optimized and its characteristic of absorption is analyzed. Optimal design of three layers microperforated panel can get more satisfactory absorption curve than double microperforated panel during the usual noise frequency area. Its absorption coefficient is almost equale to convention absorb material. A experiment is carried out to prove this optimal design.