Abstract: This paper explores the improving effect and strengthening mechanism of xanthan gum and guar gum on tailing sand. It examines the interaction between different water-soluble plant gums and tailing sand by unconfined compressive strength,scanning electron microscopy and industrial CT scanning tests. The test results show that the optimal ratio of xanthan gum and guar gum to soil is 1%,and the compressive strength increased with the increase of the curing age. After 28 days and compared to untreated tailing sand,the strengths of xanthan gum and guar gum-improved soils increased by 266.84% and 262.33%,respectively. The microscopic tests show that as the curing age grows,colloids in the soil change into "small cemented and wrapped granular particles",and the internal cracks and pores gradually decrease. The porosity of tailing sand is 14.55% while the porosities of 28 d xanthan gum and guar gum soils are 3.08% and 3.26%,respectively. Moreover,the influence of the colloid-polymer optimal mixture ratio and curing age on the compressive strength,microstructures,and internal fracture pores of soil are obtained and presented.