[Objective] The effects of soil moisture content and root area ratio on the soil consolidation effect of Medicago sativa and Euphorbia hypericifolia root systems and the interaction mechanism of root-soil were studied in order to provide scientific basis for selecting plant species and controlling soil moisture content in ecological restoration of mines. [Methods] Wild M. sativa and E. hypericifolia were observed on a Haizhou open pit mine slope in Burin City, Liaoning Pvocince. Tests were conducted to determine the tensile properties of the root systems. The root-soil complex shear test was used to determine the optimum moisture content of the root systems of the two plants. The root-soil composite shear optimization test was conducted based on the optimal moisture content to determine the optimal root area ratio for soil consolidation efficiency. [Results] ① The tensile resistance of the root systems of the two species increased as a power function of root diameter. The tensile strength of the root systems decreased as a power function of root diameter. ② The cohesive force of the vegetative soil and the two root-soil complexes tended to increase and then decrease with increasing moisture content, and the angle of internal friction tended to decrease with increasing moisture content. ③ The M. sativa and E. hypericifolia root systems had the greatest soil consolidation effect when the moisture content was 25% and 21%, respectively. ④ At the optimal moisture content, the greatest soil consolidation efficiency was achieved when the root area ratios of the M. sativa and E. hypericifolia root systems were 0.04% and 0.08%, respectively. [Conclusion] The morphological and mechanical effects of the E. hypericifolia root system made it the superior species because of its greater soil consolidation than the M. sativa root system.