In order to study the influence of the grain orientation and grain morphology of Zr-4 on the stress distribution of the alloy matrix at 500℃, the grain deformation of the Zr-4 has been simulated by the finite element method according to three different grain morphology models with a variable of the different (11-20) oriented grains’ proportion. And the stress that acts on the matrix when the oxide film is formed is applied to the simulation as the load. The simulated results show that the grain morphology and the proportion of oriented grains have obvious influence on the internal stress distribution of the matrix grains. With the increase of the proportion of (11-20) oriented grains (14.6%-85.4%), the stress concentration in the Zr-4 matrix becomes more obvious, and the stress concentration will promote the failure of the Zr-4 during corrosion. The more likely to the equiaxed crystal of the grain, the more homogeneous the stress distribution is in the model, and the less of the stress value is, which is beneficial to improve the corrosion resistance of the alloy.