In the current study, a pot intercropping experiment was carried out to study the root interactions between Sedum plumbizincicola and Schefflera arboricola, and the plant growth and cadmium (Cd)/Zinc (Zn) uptake of the intercropping system. When S. plumbizincicola intercropped with S. arboricola, the root-root interaction inhibited the root growth and shoot Cd and Zn uptake of each other. Cd and Zn removal rates of the intercropping system were lower than that of S. plumbizincicola single planting for 30.0% and 30.6% respectively. Soil nutrient properties were changed by the roots of the two plants, and there was competitive and complementary utilization of soil K and P, respectively. Both the concentrations of soil available K and P were not decreased to the deficit level, indicating that nutrient competition may not be the main factor of the root-root interaction of the two species. In a supplementary hydroponic experiment, the root exudates of S. arboricola had an inhibitory effect on the growth and Cd uptake of S. plumbizincicola, indicating the allelopathy inhibition was one of the crucial mechanisms of root-root interaction between the two species likely.