The invention discloses a liquid-state slag flow control device having rapid replacement and accident disposal functions. The liquid-state slag flow control device having the rapid replacement and accident disposal functions comprises a slag ladle. A liquid-state slag inlet is formed in the upper portion of the slag ladle and allows liquid-state slag to flow into the slag ladle. The bottom of theslag ladle is provided with a slag falling device provided with a rotating disk. The side wall of the bottom of the slag ladle is provided with a slag ladle accident deslagging metering nozzle and a normal work metering nozzle. A seal cover covers the outside of the normal work metering nozzle. A stopper rod pushing device outer cavity is formed in the seal cover in the first direction. An accident flow guide groove device inner cavity and an accident slag outlet are formed in the seal cover in the second direction. The first direction is perpendicular to the second direction. The slag fallingdevice provided with the rotating disk comprises the rotating disk and a plurality of slag falling straight pipe sections installed on the rotating disk, wherein only one slag falling straight pipe section is in use, and others are standby. The liquid-state slag flow control device can achieve the liquid-state slag accident disposal function, the flow and temperature monitoring and controlling functions and the slag falling straight pipe section rapid replacement function, and therefore a system can cooperate more stably, more safely and more reliably. The liquid-state slag flow control device can be widely applied to liquid-state slag pelletization waste heat recycling systems.