In order to systematically explore the combustion characteristics of an anthracite used in iron ore sintering, the combustion characteristics and microcrystal structure of Sihe and Chengzhuang lump anthracite, its cleaned powder coal and coke powder are compared and analyzed by TG-DTG, XRD and other methods, the ash index (ρ_Al) is proposed to evaluate the influence of ash on combustion performance, and the influence of solid fuel particle size on the combustion characteristics of cleaned powder coal and coke powder of Sihe and Chengzhuang is analyzed. The results show that the ignition and combustion perfomance of Sihe and Chengzhuang cleaned powder coal are significantly improved, the ash index value is significantly reduced, and the combustion characteristic parameters are closer to that of coke powder. With the increase of solid fuel particle size, the average combustion rates of Sihe and Chengzhuang cleaned powder coal and coke powder are decreased by 22.57%, 10.97% and 15.53%, respectively. Chengzhuang cleaned powder coal has the best stability when burned in the batching mode of mixed particle size, and it has advantages over coke powder for sintering production. The XRD analysis results show that, compared with Sihe cleaned powder coal, the microcrystalline structural parameters of Chengzhuang cleaned powder coal and coke powder are more similar, which is consistent with the experimental results of thermal analysis.