Imageable composition for photosensitive negative lithographic printing plate and plate making method thereof

The invention discloses an imageable composition for a photosensitive negative lithographic printing plate and a plate making method of the imageable composition. The imageable composition comprises the following components in parts by mass: 25-65 parts of a free radical polymerizable compound, 0.5-25 parts of a photoinitiator, 10-60 parts of a binder and 1-20 parts of a development accelerator. The plate making method comprises the following steps: (1) coating the imageable composition on a substrate with a hydrophilic surface or a hydrophilic layer to obtain a photosensitive negative lithographic printing plate precursor; (2) exposing the lithographic printing plate precursor with laser according to a desired image, thereby forming an exposed region and an unexposed region; and (3) removing the unexposed region from the exposed printing plate precursor through a developing process to obtain the required lithographic printing plate. By adopting the imageable composition and the plate making method, the flexi