In view of the alkali metal erosion of furnace lining materials in the process of disposing metallurgical solid waste in the high-temperature direct reduction process of rotary hearth furnace, the erosion behavior of such four different alkali metal compounds as NaCL, KCL, Na₂?CO₃? and K₂?CO₃? at high temperature is studied. The effects of different alkali metal compounds on the erosion behavior of the furnace lining materials are systematically analyzed by using the strength test method and the high temperature erosion method, and the erosion mechanism of alkali metals on the furnace lining materials is revealed by combining SEM, EDS, XRD and other detection methods. The results show that the alkali metal compounds will erode and damage the furnace lining material, which will reduce the compressive and flexural strength of the furnace lining material. The compressive strength of the K₂?CO₃ and Na₂?CO₃? furnace lining materials is reduced by 20.6% and 15.9% , respectively, and the flexural strength is reduced by 19.8% and 15.1% , respectively, compared with the blank sample, and the compressive strength of the furnace lining materials added with KCL and NaCL is reduced by