Abstract: With industrial development, the concentration of heavy metals such as cadmium (Cd), lead (Pb), mercury (Hg), and zinc (Zn) in soil has increased significantly owing to human activities. This poses serious threats to plant growth and human health, garnering widespread concern. Cd, in particular, exhibits high mobility in soil. It is predominantly absorbed by plant roots, transported through the xylem, and accumulated in various organelles and sub-organelles within plants. As a non-essential element for plant growth, Cd is toxic even at low concentrations, affecting plants at morphological, physiological, biochemical, and molecular levels. For example, Cd inhibits seed germination, hinders root elongation, and reduces overall plant height. It enters the chloroplasts, compromising the integrity of the chloroplast membrane system, which leads to decreased chlorophyll content, leaf yellowing, reduced photosynthesis, and, in severe cases, plant death. At the cellular level, Cd induces oxidative stress, triggers lipid peroxidation, and generates excessive reactive oxygen species (ROS). These processes damage cell membrane integrity, disrupt cellular functions, and cause oxidative damage. Through long-term natural selection and environmental adaptation, some plants have developed a high tolerance to Cd, with their above-ground parts capable of accumulating heavy metals at concentrations more than 10 times those of ordinary plants. These plants are known as Cd hyperaccumulators. Hyperaccumulators can thrive in soils contaminated with high Cd concentrations by employing various strategies to mitigate Cd adverse effects. These include confining heavy metals within cell walls, isolating them in vacuoles, and secreting compounds such as phytochelatins (PCs) and organic acids (OAs) to bind free Cd ions and form Cd-chelates, thereby reducing Cd mobility. Specialized transporters facilitate the uptake of Cd ions and Cd-chelates from the soil into the plant, subsequently transporting them to aerial parts and distributing them across organelles and sub-organelles to minimize Cd-induced tissue damage. To counteract oxidative damage caused by ROS, plants produce enzymatic antioxidants (e.g., superoxide dismutase, catalase, peroxidase, glutathione reductase) and non-enzymatic antioxidants (e.g., ascorbate, carotenoids, flavonoids, phenols), which help maintain cellular integrity and support plant function. At the molecular level, hyperaccumulators mitigate Cd stress by enhancing the transcription of calcium ion signaling pathways and hormone-stimulated transcription factors. This enhancement facilitates the expression of various genes across different plant organs, helping to alleviate the stress and toxic effects of Cd. To provide a comprehensive understanding of the physiological, biochemical, and molecular mechanisms underlying the absorption, transport, and accumulation of Cd in hyperaccumulator plants, this paper systematically reviews the role of root exudate chelation, the influence of plant hormones, and the regulation of transporter gene overexpression. Overexpressed genes not only enhance the absorption and transport of Cd but also influence plant biomass, chlorophyll content, antioxidant mechanisms, organic acid synthesis, and root exudate production. These interconnected mechanisms work together to sustain normal plant growth under Cd stress. This review can offer new insights and reference points for future research on hyperaccumulator-based phytoremediation of Cd-contaminated soil.