The present invention discloses a coating apparatus and a control method thereof, and the coating apparatus comprises: a base material storage tank for storing base materials and which is connected with a base material concentration adjusting device that is used for adjusting base material concentration; a feed pump having an inlet connected with the base material storage tank; a reversing valve assembly having an inlet, a first outlet and a second outlet, wherein the inlet of the reversing valve assembly is communicated selectively with at least one of the first outlet and the second outlet, the inlet of the reversing valve assembly is connected with an outlet of the feed pump, and the first outlet of the reversing valve assembly is connected with an inlet of the base material storage tank; a coating tank connected with the second outlet of the reversing valve assembly; a concentration detection device for detecting a concentration of a base material introduced into the coating tank. According to the coating apparatus of the invention, it is possible to cyclically mix the base materials in the base material storage tank to improve uniformity of the base material concentration. It is also possible to detect the concentration of a base material entering the coating tank to ensure coating quality and effect.