The invention relates to the technical field of converting furnace temperature monitoring, in particular to a system for monitoring the temperature of melt in a settling pond of a flash converting furnace. Comprising an on-line temperature measuring device; the temperature online measuring device is used for detecting the temperature of a settling pond of the converting furnace and the temperature of melt in the settling pond in real time; a data visualization module; the data visualization module is electrically connected with the temperature on-line measuring device. An intelligent control hub; the intelligent control center is electrically connected with the data visualization module; an instruction module; and the instruction module is electrically connected with the intelligent control center, and modifies a corresponding operation bar on the DCS according to an adjusting instruction output by the intelligent control center. The system can replace manual work to detect the temperature of the melt in the settling pond in real time, the working mode of the converting furnace is adjusted according to a detection structure, the melt temperature monitoring efficiency is improved, and meanwhile the working efficiency of the converting furnace is improved.