The present invention relates to a photosensitive resin composition, a preparation method thereof, and a dry film resist comprising the same. More particularly, the photosensitive resin composition of the present invention is directed to a photosensitive resin composition including a) an alkali-soluble acrylate resin, b) a cross-linking monomer having at least two ethylenic double bonds, and c) a phosphine oxide based photopolymerization initiator and an acridon based photopolymerization initiator. According to the photosensitive resin composition and the dry film resist, it is easy to finely pattern using a laser direct image with high density and the dry film has excellent sensitivity, resolution, and adhesiveness to the substrate.