###### Abstract  
The effects of different concentrations of cadmium and 2,2\({}^{\prime}\),4\({}^{\prime}\),5,5\({}^{\prime}\)-hexabrominated diphenyl ether (BDE-153) on the growth and related physiological and biochemical indexes of _Amaranthus mangostanus_ L. (amaranth) were studied. The results showed that the presence of BDE-153 promoted the absorption of Cd by the amaranth and inhibited the migration of Cd from the roots to the shoots. At the same time, 0.1 mg/L of Cd had a synergistic effect on the migration of BDE-153, but 5 mg/L Cd inhibited the accumulation of BDE-153 in the aboveground part of the amaranth. In addition, the kinetics of the uptake of pollutants by the amaranth showed that both Cd and BDE-153 could be transported by amaranth, but Cd and BDE-153 were mainly enriched in the roots, and the presence of Cd may cause a lag in the uptake of BDE-153 in the shoots. Compared with the control group, the biomass of the amaranth affected by BDE-153 and a high concentration of Cd (5 mg/L) decreased by 30.2-49.5%, the chlorophyll content decreased by 43.0-60.3%, the Evans blue increased, and the MDA content was higher. The activities of superoxide dismutase (SOD) and catalase (CAT) also decreased with an increase in the BDE-153 concentration. This indicates that the interaction between BDE-153 and a high concentration of Cd (5 mg/L) is more toxic to amaranth than single Cd pollution. This paper provides the necessary data support for phytoremediation of heavy metal and organic compound pollution. industrial discharge. The Cd content in the soil of China's irrigation area ranged from 0.01 to 54.05 mg/kg, and the average Cd concentration in the soil of its mining and smelting areas was four times that of the irrigation area. The Cd content in urban farmland was relatively low, ranging from 0.05 to 3.15 mg/kg. The average content of Cd in the cultivated soil in China is about 0.27 mg/kg, which is higher than the background value (0.097 mg/kg) measured by China National Environmental Monitoring Centre in 1990 [5]. This indicates that most of the agricultural soil suffer from Cd pollution, and Cd has the characteristics of stability, accumulation, and being difficult to eliminate after entering the soil. Therefore, after the soil is polluted with Cd, it is easy for Cd enrichment to be caused in crops [6]. The long-term consumption of Cd-contaminated vegetables by humans will lead to a gradual increase in the Cd accumulated in the body [7; 8; 9]. Long-term Cd exposure will cause symptoms such as bone atrophy, osteomalacia, and bone curvature, which will lead to natural fractures [10]. The chemical properties of polybrominated diphenyl ethers are very stable and they are easily disassembled into the soil due to unreasonable e-waste discharge, resulting in polybrominated diphenyl ethers being adsorbed into the soil. For example, the average concentration of PBDEs in the soil of Shanghai, China, was 735 ng/g [11], and the average concentration of PBDEs in the soil of an e-waste treatment site in Taizhou, Zhejiang, China, reached 625 ng/g (dry weight, dw), which was higher than the concentration in the surrounding area (mean: 209 ng/g) [12]. They experience persistent, long-distance migration and bioaccumulation in the environment and can enter the human body through the food chain and endanger human health [13], mainly manifested in liver damage, thyroid hormone interference, and neurodevelop and reproductive system damage. For example, studies have found that exposure of fish embryos to PBDEs could lead to the increased malformation and mortality of the juvenile fish [14]. 2,2',4,4',5,5'-hexabrominated diphenyl ether (BDE-153) is one of the most widely studied hydrophobic (log Kow = 7.9) PBDE congeners and has been detected in the air, soil, surface water, vegetables, and fruits, and even in human blood and serum [15; 16; 17; 18; 19; 20].