Abstract: The possible geometrical structure of aluminum hydride Al2Hn(n=1-6) clusters has been optimized computation,based on density functional theory B3P86 method and at the Dunning related consistent base group cc-PVTZ level.The configuration geometric parameter,electronic structure,vibrational frequency and spectrum of the most stable structure has been obtained, and given total energy (ET),binding energy (EBT),average binding energy (Eav),ionization potential (EIP),energy crack (Eg),Fermi level (EF) and so on.The results indicate that the ground state of aluminum hydride clusters all are 1 heavy condition,the electronic state is when n is odd number and it is when n is even number,respectively.In all aluminum hydride clusters,they belong to hydrogen bridge type.The ultimate analysis of the infrared spectrum covers the average binding energy,the ionization potential,the energy gap and Fermi level and their characteristic.It has shown that Al2H6 is the most stable molecule in (Al2Hn(n=1-6),the H-Al bridge bond key length is longer than that of the terminal linkage, while the infrared intensity of strongest peak is of maximal value.