Under the " dual carbon" strategic goal, coal gasification technology will be an important development path in China′s futurecoal industry. In the promotion and application of coal gasification technology, the flow behavior of slag seriously affects the stable operation time of gasifiers, indirectly affecting the quality of synthesis gas and the heat loss of furnace walls. The effective prediction model forslag flow characteristics to solve flow parameters has attracted much attention. This study discussed the existing predictive models for theflow characteristics of slag in gasifiers and looks forward to the future research directions of predictive models. At present, prediction models can be divided into one-dimensional prediction models and two-dimensional prediction models based on the dimension of slag flow.Both one-dimensional steady-state and non-stationary prediction models have gone through the stages of construction and improvement.The two-dimensional prediction model is still in the construction stage due to the lack of relevant mathematical formula descriptions andflow concept assumptions. The calculation accuracy of the model can be improved by considering the temperature distribution of liquidslag, the selection of additional stress, the selection of critical viscosity, and the treatment of slag viscosity. Looking ahead to the future,the application scenarios of one-dimensional prediction models require more comprehensive regulations and more detailed analysis is needed for the parameters solved by steady-state and non-stationary prediction models. The construction theory of two-dimensional predictionmodels requires a more detailed breakthrough, clarifying the priority of slag flow in the axial and circumferential directions under nonsteadystate conditions. The calculation accuracy of slag flow prediction models needs to be comprehensively improved, with a focus on factorssuch as the non-constancy of slag properties, non-uniformity of melting, fluctuation of flue gas flow rate, and diversity of coal ash types.