The effect of the homogenization treatment with an electric field on the microstructure of 2091 Al-Li alloy is investigated The results show that the homogenization treatment with an strong electric field promotes the homogenization of Al-Li alloy, increases the solubility of alloying element,induces the homogeneous nucleation of T 1 phase and results in the increasingyield strength In the same time, the strain ageing treatment after the combinedhomogenization treatment increases significently the mechanical properties of 2091 Al-Li alloy because of the uniform and fine second phase precipitation