Abstract: The experiment of air flowing high-temperature steel slag particles was done and the experimental correlation of non-di-mensional average Nusselt number was fitted. A three-dimensional numerical simulation of air-cooled high-temperature steel slag parti-cles was performed to study the criterion equations in different conditions and to analyze the influencing factors of air sweeping solid steel slag particles. The experimental correlation and numerical calculation of air-cooled solid steel slag particles were gained, and the error between the experimental and numerical calculation is very small, which verifies the reliability of the SST k-ω model. The results show that the average Nusselt number of slag particles increases with the increase of streaming Reynolds number, particle diameter, and air velocity. The particle diameter effect on the average Nusselt number is larger than the air velocity under the same conditions. The influence of the steel slag particle diameter on the solidification time is the largest, the thermal conductivity is the second, and the air stream temperature is the smallest.