According to ab initio calculations, the differential scattering cross sections between He and HF, HCl, HBr are calculated and compared with experimental data. The results show that the calculation method can calculate comparatively accurate interactional potential. As halogen atom radius increases, at 0°, the minimum of interactional potential shallows, the position of potential well moves into the distance, and anisotropic property becomes prominent, while at 180°, the minimum of interactional potential depens, the position of potential well moves into the distance, and the isotropic property becomes obvious. The potential well depth under T structure is larger than that of linear structure. With the increases of halogen atoms radius, a more spherical symmetry is exhibited, and it can be seen obviously that contributions of radial coefficients V0, V1, V2, V3, ··· decrease gradually, which is important to understand the study of excited state dynamics.