The tensile strength and fatigue crack propagation rate test were carried out for cold rolled, warm rolled and full annealed Al-6Mg-0.8Zn-0.5Mn-0.2Zr-0.2Er alloy. The microstructure before fatigue test , the fatigue fracture and crack propagation path were observed by using electron back-scattered diffraction(EBSD), transmission electron microscope(TEM) and scanning electron microscope(SEM) in order to analyze the effects of microstructure on tensile property and fatigue crack propagation property. The results show that the fatigue crack propagation rate of warm rolled alloy with high strength is much slower than the cold rolled. The microstructure characterization shows that the warm rolled alloy has more subgrain boundaries than that of the cold rolled and full annealed alloys due to dynamic recovery during warm rolling. This kind of microstructure is conducive to the improvement of yield strength and fatigue crack propagation resistance.