Dislocation properties of {110} in Al-Dy intermetallic compound with B2 structure were studied by truncation approximation.The results show that the Burgess vector is <110>, the core width of the directional screw, edge and mixed dislocation should be greater than <100> irection. Their corresponding unstable stratification energy is present γ_us<110> < γ_us<001>. It can be seen that the unstable stratification energy is one of the important factors affecting the dislocation properties of intermetallic compounds with B2 structure. B2-AlDy slip system is <111>. For the dislocation of {110}, except for the dislocation with a dislocation Angle of 54.7°, the elastic strain energy of other dislocation angles is greater than the misfit energy, and their phases are always opposite in the same period.When the dislocation Angle is 54.7°, the misfit energy is greater than the elastic strain energy, and both of them are in phase in the same period. In general, for the {110} plane of B2-AlDy, <100>, <110> and <111> direction of dislocation, with the reduction of dislocation angle (except the <111> direction for the dislocation angle of 54.7°), the total energy and the corresponding stress increase in turn.