Gasification technology is the leading technology of the coal chemical industry, and the airflow bed gasifier is the direction oflarge-scale gasification due to the flexible fuel application and high conversion rate. As the raw material components or operating condi⁃tions change, the slag may exhibit non-Newtonian fluid properties due to crystal precipitation during the flow process, resulting in poorslag discharge. Therefore, the crystal precipitation behavior of the slag in the furnace has important guiding significance for controlling therheological properties of the slag and the stable operation of the equipment. Research on the crystallization behavior of non-Newtonianslags was summarized, the influencing factors of the main components and cooling conditions were analyzed. The driving force of crys⁃tal growth varies with different undercooling degrees, thereby affecting the crystal growth rate. Increasing the cooling rate leads to insuffi⁃cient crystal incubation time and thus small crystals. When the cooling rate exceeds the critical cooling rate, the slag takes on a vitreousstate. The changes in the main components of the slag lead to changes of the diffusion properties as well as the crystal types. An increase inthe alkalinity of the melt leads to an increased crystallization capacity of the slag. In addition, different crystal types, the size and shape ofthe crystals, the crystallization reaction at the solid-liquid interface, and the crystal growth rate, etc. all undergo changes, resultingin changes in rheological properties. Therefore, the growth characteristics of several common crystals in slag (Anorthite, Melilite and Spi⁃nel) were summarized, as well as the influence of the crystals on the rheological properties of the slag. For non-Newtonian slags, the crys⁃tal precipitation types and corresponding crystal characteristics are still unclear and need to be further studied. Adjusting the rheologicalbehavior of slag by forecasting and controlling the crystal growth will realize the prediction of the viscosity change of the liquid slag layer,which is significant for optimizing the flow of slag discharge furnace.