The utility model discloses a coating dip-coating tank which is characterized by comprising a tank body for containing liquid coating, and a set of liquid detection pipeline is arranged on the tank body. The liquid detection pipeline comprises a liquid taking pipe, a detection pipe and a liquid return pipe, wherein the liquid taking pipe and the liquid return pipe are all horizontal pipes, and the liquid taking pipe is lower than a working liquid level in the tank body and higher than the liquid return pipe. A pipeline switch is further arranged on the liquid taking pipe, and the detection pipe is a vertical pipeline with an open upper end. The middle of the vertical pipeline is communicated with an outlet of the liquid taking pipe, and a lower pipe port of the vertical pipeline is communicated with an inlet of the liquid return pipe. A pipeline switch is further arranged on the lower portion of the vertical pipeline. The coating dip-coating tank is further provided with a detection device which can reflect states of coating liquid so as to conveniently carry out detection on the conditions of not shutting down a production line and not entering the tank.