The invention provides a spreader, a coating device and a coating method. The spreader provided by the invention is capable of quickly discharging air bubbles inside the spreader to the outside. The spreader comprises a first supply port (31) for supplying the coating solution; a first manifold (11) connected with the first supply port (31); a spit-out seam (22) for spitting out the coating solution; a second manifold (12) connected with the spit-out seam (22); and a connection throttling flow path (21) connected with the first manifold (11) and the second manifold (12). The first manifold (11) is connected with a first discharge port (41) for discharging air bubbles inside the first manifold (11) to the outside. The second manifold (12) is connected with a second supply port (32) for supplying the coating solution and a second discharge port (42) for discharging air bubbles inside the second manifold (12) to the outside.