Abstract: The effects of solution time and solution temperature on the microstructure and formability of ultra-high strength 7055 aluminum alloy thin strip containing Er element after solid solution were studied by EBSD, tensile test and cupping test. The results show that the cupping value of thin strip samples first increases and then decreases with the increase of solution temperature or solution time. The optimum solution treatment system of the thin strip sample is 475 ℃×1 h, under this solution heat treatment condition, the yield ratio, elongation, strain hardening exponent and cupping value are 0.67,27.3%, 0.21 and 8.99 mm, respectively. The average grain size, recrystallization fraction and low angle（＜15°） grain boundaries ratio of thin strip sample are 15.5 μm, 84.7% and 27.8%, respectively.