Abstract: Taking AZ31 magnesium alloy rolled sheet with the thickness reduction of 30% as the research object, the static recrystallization process of the deformed structure of the sample was observed by in-situ SEM and EBSD experiments,and the competitive relationship between the shear band and twin recrystallization of the AZ31 magnesium alloy sheet during the annealing process was studied. The results show that the competitive relationship between the shear band and twins on the preferential nucleation of recrystallization in the annealing process is determined by the energy relationship, and mainly depends on the density of the shear band. When the shear band is dense, it can nucleate before the 1011-1012 secondary twins. When the shear band is thinner, 1011-1012 secondary twins can be used as a preferential nucleation site for recrystallization.