The hydrogen absorption behavior of Ti70 alloy was studied by electrolytic hydrogen charging and then characterized via hydrogen analyzer and metallographic microscope. The relationship between the hydrogen content with the microstructure, diffusion direction and specific surface area of Ti70 alloy was examined. The results show that the increased continuity of β phase strongly facilitates the absorption capacity of Ti70 alloy, whereas, the β phase provides more tetrahedral interstitial sites, becoming the easier diffusion path for H. The distribution of H in the alloy is macroscopically non-uniform. The H content shows a sharp decreasing from the surface to the interior. The diffusion of H along the thickness direction is much more difficult than the rolling direction. This should be attributed to the blocking effects caused by the elongated α phase in the thickness direction and the more continuous β phase along the rolling direction. The H absorption capacity was found to increase with the specific surface area of the alloy sample, which further proved that the absorbed H is not sufficiently diffused in the alloy sample, as a result, the larger the surface area per unit volume, the higher the H absorption capacity.