Provided is plastic granulating water cooling drying equipment. A water cooling dicing cutter is fixed at the tail end of a material extruding machine, an inlet of a transport pipeline is communicated with a discharge port of the water cooling dicing cutter, an outlet of the transport pipeline is communicated with a dry cooling tower, an upper opening of the dry cooling tower is a feed opening, a lower opening of the dry cooling tower is a discharge port, material distribution tower boards and material receiving tower boards are arranged at intervals in the vertical direction, each material distribution board is shaped like a cone, the vertex of the material distribution board is located at the discharge port, material channels are formed by gaps between the lower edges of the material distribution boards and the tower wall, the inverted truncated and bottom surface-free cone-shaped material receiving tower board is arranged on the lower portion of each material distribution tower board, the upper edges of the material receiving tower boards are fixedly connected with the tower wall, the interior of each cone is used for receiving materials, the cut top is a discharge port of each material receiving tower plate, the vertex of each material distribution tower plate is arranged at the discharge port of the corresponding material receiving tower board, after bio-based and biodegradable plastics pass through a granulator, water cooling is conducted, and drying is conducted through a drying tower. By adopting a water-cooling and air-cooling combined means, uniform granulation is achieved, water in granules is reduced, the production efficiency is improved, and the yield is increased.