Molecular dynamics was employed to study the migration and coalescence of He atom and He dimmer in Ti lattice which contains He-vacancy cluster. The influence of the ratio of helium to vacancy （He density） of the cluster and the He number of the cluster on coalescence of He and He-vacancy cluster in Ti lattice is studied. It is found that anisotropic diffusion is independent of the He-vacancy cluster in Ti lattice. The coalescence of helium and He-vacancy cluster is mainly along the ［001］ direction. The coalescence of He dimmer and He-vacancy cluster is faster than the coalescence of He atom and He-vacancy cluster.