The dislocation properties of intermetallic compound (IMC) B2-AlPr in {110} plane is studied in detail based on the truncated approximation method in this paper. The results suggest that the core width of screw dislocation and edge dislocation of Burgers vector < 100 > is wider than that of < 110 >. Meanwhile, their unstable-stacking-fault energy ( $$ \gamma_{\text{us}} $$ γ us ) of $$ \gamma_{\text{us}} \langle 110\rangle > \gamma_{\text{us}} \langle 001\rangle $$ γ us ⟨ 110 ⟩ > γ us ⟨ 001 ⟩ indicates that the unstable-stacking-fault energy performs very important function on the core width of screw dislocation. The easiest slip system of B2-AlPr is < 111 > {110}. The lattice misfit energy is always less than elastic strain energy except the dislocation angle with 54.7°. The phase position of misfit energy and elastic strain energy is always showing opposite phases. However, the misfit energy is greater than elastic strain energy for 54.7° dislocation, and shows the same phase. The misfit energy, elastic strain energy, total energy and the corresponding stress decrease with the increasing of dislocation angle.