Abstract: Zhundong Coal was blended with the different proportions of other coals. The CCD (Charge Cou-pled Device) monitoring system and sintering probe were applied to carry out real-time on-line monitoring on the sintering and melting characteristics of blend ash. The results showed that when Zhundong coal and Beitashan coal,Zhundong coal and Wudong coal were mixed according to the mass ratio of 9 ∶ 1,8 ∶ 2 and 7 ∶ 3 respectively,the sintering and melting of ash samples could be inhibited,and the slagging could be prevented. The cross-section of the sintered ash block was characterized by a three-layer structure,of which color and sintering degree of each layer were significantly different. The degree of sintering from inner to outer layer gradually increased,and as the proportion of coal blending increased,the molten material of the outermost layer decreased. At the same time,the height and area shrinkage of each sintered ash block was obtained by using the GUI digital image processing system developed by Matlab software. The height and area shrinkage of pure Zhundong coal ash block at the final moment of sintering were 0. 125 and 0. 225,respectively. It was found that the coal blending had a great influence on the height and cross-sectional area of the ash samples,and as the proportion of coal blending increased,both height and area shrinkage rates decreased. Analysis by XRD (X-ray Diffraction) technology revealed that the change of mineral phase was closely related to the type and proportion of coal blending but had little effect on the minerals of the outer layer. The main component of the outer mineral phase was anorthite ( CaAl2Si2O8 ). The SEM ( Scanning Electron Microscope) analysis showed that after coal blending the diameter of outer pore structure was reduced and the outer layer matrix exhibited a smooth and dense structure. At the same time,the chemical composition of the surface of each sintered ash block was analyzed by EDX(Energy Dispersive X-ray Spectroscopy). The contents of Na,K and S elements in the surface of each sintered ash block were generally reduced from inner layer to outer layer. The Ca,Al and Si elements contents showed an increasing trend,and the evaporation of alkali metal elements decreased after coal blending.