Vertical layered MoSe2 nanosheets have been synthesized via rapid selenization of a magnetron sputtered Mo film with a large number of penetrating microcracks. The phase microstructure and morphologies of Mo and MoSe2 films were evaluated by X-ray diffractometer, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy. The results indicate that a relatively high argon pressure during the sputtering process allows Mo films to deposit with a multi-crack structure. The microcracks increase the inner surface area of Mo films and provide a rapid transmission tunnel for selenium diffusion, which allows MoSe2 nanosheets to grow vertically with a c-axis // substrate texture. The growth mechanism for vertically aligned MoSe2 films has been proposed based on the experimental results. The growth orientation of MoSe2 film can be precisely controlled by adjusting the density of Mo film precursor under the same selenization condition. These findings provide a new strategy for the preparation and application of highly orientated MoSe2 film.