Using the molecular dynamics method, we apply tensile loads in different directions to a preset-microcracks α-Ti model. Through the observation of the changes in the pores and dislocations of the α-Ti model, we reveal the mechanism of the pore growth and the potential energy distribution. We found that: under the tensile load along [0001], the perpendicular direction of the close-packed plane, the preset crack in the model closes up, the clusters on both sides occupy the gap of crack defect, showing obvious necking phenomenon, and part of the HCP lattice transform into the FCC lattice to plane, which derive a variety of dislocations with higher density in the crystal. Therefore, it can bear more press. Under the tensile load along [12-30], the dislocation types are mainly 1/3 [1-210] with less total length than in [0001]. The crack grows into a circular cavity. The cavity and sliding band divided the absorption energy regions into four parts. The lattice transformations are mainly from HCP to amorphous structure. The direction of the slip band depends on the material lattice and the position depends on the initial crack. Load on [0001] makes the necking phenomenon of the model prominent, and the crack defect vacancies are occupied by the clusters on left and right sides. Therefore, when loaded on [0001] the α-Ti have better plasticity and ductility than loaded on [12-30].