Fluidized preheating combustion technology used in rotary kilns can effectively reduce the fuel consumption per unit product and has advantages such as wide fuel adaptability and low NOx emissions. However, compared to pulverized coal, the combustion characteristics of preheated fuel are significantly different. This work employs computational fluid dynamics (CFD) to study the effects of preheating temperature, excess air coefficient within the rotary kiln, and the momentum of the axial flow air passage of the burner on the combustion process of high-temperature preheated fuel within the rotary kiln. Combining the author's previous research on the swirl number of multi-channel burners, an orthogonal design method combined with matrix analysis is used to obtain the importance of the effects of these four factors on combustion characteristics and the optimal parameter combination for comprehensive combustion performance. The results show that as the preheating temperature increases, the flame becomes thicker and shorter; as the excess air coefficient increases, the flame first becomes longer, then shorter; as the momentum of the axial flow air passage of the burner increases, the flame first becomes shorter and thicker, then longer and thinner. The importance of the effects of these four factors on combustion characteristics is in the order of preheating temperature>momentum of the axial flow air passage of the burner>swirl number>excess air coefficient. The optimal parameter combination is a swirl number of 0.2, a preheating temperature of 850℃, an excess air coefficient of 1.1, and a momentum of the axial flow air passage of the burner of 0.5 N/MW. The optimized conditions, compared to the original conditions, result in a 47% increase in flame length, a 37% increase in the average heat flux of the wall in the firing zone, and an 80% increase in the maximum heat flux of the wall in the firing zone.