Abstract: The application of tailings paste backfill technology is becoming increasingly widespread. Yield stress holds significant guiding importance for key processes such as paste thickening and pipeline transportation. Based on an analysis of existing research, it is proposed that the flocculated network structure and the particle skeleton structure are critical factors influencing yield stress. Utilizing fractal theory, the morphological characteristics of the flocculated network structure were analyzed, resulting in a mathematical relationship describing the equivalent diameter of flocs in terms of the median particle size and volume fraction of clay−sized particles, as well as the fractal dimension of the flocs. Building on this, and considering the combined effect of the flocculated network structure and the particle skeleton structure on yield stress, a predictive model for paste yield stress was established. Three types of tailings were prepared into experimental paste samples with varying solid volume fractions. The adaptability of the predictive model was then validated and analyzed using measured yield stress data from these experimental paste samples.The results indicate that the flocculated network structure of paste exhibits typical fractal characteristics. The fractal dimension (n_f) of the flocculated network structure for the three tailings pastes ranges from 2.63 to 2.72. A higher proportion of clay−sized particles (d≤2 μm) in the tailings correlates with a larger fractal dimension.Under the same solid volume fraction conditions, a higher proportion of fine particles (d≤ 20 μm) leads to a denser development of the flocculated network structure and consequently a higher yield stress.A more discontinuous gradation distribution of coarse particles (d > 20 μm) results in stronger frictional interactions within the particle skeleton structure, leading to a higher yield stress.The established yield stress predictive model demonstrates good fitting performance and possesses practical value. It provides a new approach for analyzing the rheological properties of similar high−concentration slurries.