A cleaning apparatus for concentration controller of coating machine may include a pulse bubble generator and a container used for cleaning a concentration controller of a coating machine and a tube thereof. The pulse bubble generator has a bubble-generating end connected to the container through a pipe, and the container is filled with a plentiful detergent. The pulse bubble generator is configured to pump air into the detergent with a pulse per time, and a large amount of detergent bubbles are adapted to be generated in the container. The detergent bubbles are configured to be pumped by the concentration controller into the tube and the concentration controller so as to complete cleaning effect of the tube and the concentration controller.