The microstructure plays a significant role in crack initiation and crack propagation in metals. In this paper, a crystal plasticity finite-element method has been developed to simulate the tensile tests on rectangle-notched, triangle-notched, and circle-notched aluminium samples. Polycrystalline aggregates are approximated by a Voronoi structure. Two sets of initial orientations are randomly assigned to the aggregate. Notch geometries after deformation, the maximum shear stresses, and crystal orientation rotations are presented and discussed. Simulation results reveal that deformation of polycrystalline aggregate is greatly influenced by both notch geometry and initial crystal orientation. The crystal orientation profoundly rotates around the thickness direction of the samples for all the notch geometries and the initial orientations.