This paper studied morphology and structure of iron-rich phase in the aluminium alloy using electrolytic separation technology, which content of iron was 0.3%, 0.6%, 1%, 0.6%, 2% and 5%.Results showed that iron-rich phase in aluminum alloy for a large number of α-FeAl3 and a small number of λ-Fe4Al13, iron-rich phase in the aluminum alloy matrix show three-dimensional distribution and its metallography look on different sections showing a sheet, plate and needle;in the iron content of 0.3%-1%, the iron-rich phase transition behavior of λ-Fe4Al13 → α-FeAl3 was closely related to iron content.lattice constant a of α-FeAl3 changed little with increasing iron content ,lattice constants c gets bigger with increasing iron content.HREM surface λ-Fe4Al13 and α-FeAl3 are tetrahedral structure, λ-Fe4Al13 lattice constants a, c substantially unchanged;α-FeAl3 lattice constants a and c change larger than the standard value when the iron content is less, and gradually stabilized with increasing iron content.