This paper discusses the optimum waveband combination in information extraction of sinking sandy land. The single band dataset, the correlation coefficient, the Optimum Index Factor (OIF) and the typical object spectral image feature curve are used to analyze the ETM⁺ multi-spectral band combination for sinking sandy information extraction in Xiwu Flag, Xilin Gol League, Inner Mongolia. The results show that: (1) Band 4 contains the greatest amount of information with the smallest correlation with other bands, band 5 and band 3 follow in their importance. The higher OIF can be obtained with the band 3, band 4, and band 5 combination, which is the best combination for sinking sandy land information extraction. (2) To select the best band combination according to remote sensing research target, different research objects have different best band combinations. To calculate the optimum band combination for relevant index for sinking sandy, one can use ERDAS and EXCEL tools to establish the function model, so as to improve the calculation efficiency. (3) In a typical ground, the feature image characteristic curve, sinking sandy land and typical steppe spectrum may be similar, as their difference is in the underground soil horizon part, while the ground vegetation in the remote sensing image through the spectra is difficult to be distinguished. The texture characteristics through images, the position relations etc are indirectly conditional to discriminate accurately. (4) Through the visual translation process for sinking sandy land with sand and grassland, wetlands, forest multiple properties, to accurately draw the space position of the sinking sandy land, one should considersinking sandy landcauses factors. In addition, because the sinking sandy land soil composition is not complete, humus layer is relatively thin, the structure is loose, the quality of the material is coarse, susceptible to damage, the foundation for sand, once damages, will lead to desertification, and the sand recovery is very difficult. So the relevant Government departments or scholars should try to attach great importance to protection and systematic research.