Using by hydroponic and potted methods, we explored different concentrations of Cd stress for Celosia cristata L. seed germination, biomass of seedlings, photosynthetic pigment, soluble protein, soluble sugar, proline and MDA contents, antioxidant enzyme activities (SOD, POD, CAT, APX) and low molecular sulfhydryl compounds (GSH, GSSG, Cys, NPT) contents to explore the ability of C. cristata L. to withstand Cd stress and its physiological mechanism, and to provide basic information for plant detoxification mechanism. The results showed that: (1) the germination potential, germination rate and germination index of C. cristata L. seeds were increased under the treatment of low concentration Cd, while the vigor index, root length and seedling length were reduced to varying degrees under Cd stress at various concentrations, and the above indicators were significantly inhibited under high concentration (50, 100 mg/L) Cd stress, and the degree of root growth inhibition was significantly higher than that of seedlings. The biomass of seedlings (whole plant fresh weight, fresh weight above ground and fresh weight underground) showed significant differences in 200 mg/L Cd stress, which decreased by 61.9%, 58.4% and 72.7% respectively compared to control, and although there was no significant difference between the rootshoot ratio and the taproot length, the overall trend decreased, greatly affecting the growth of the roots. (2) The chlorophyll and carotenoids contents of C. cristata L. seedlings were significantly reduced under the stress of 100 to 200 mg/L Cd concentration, and the contents of leaf soluble protein, soluble sugar and proline increased significantly under Cd stress, and increased significantly at 50, 150, 200 mg/L, respectively. (3) The POD and APX activities increased by 23.1%-304.2% and 160.0%-280.0% in all Cd treatments, respectively; The SOD activity decreased in all Cd stress treatments, and decreased significantly by 43.2% under 150 mg/L Cd stress; The CAT activity increased significantly by 46.6%-66.5% under 50-150 mg/L Cd stress, while decreased significantly by 59.5% under 200 mg/L Cd stress. (4) The low molecular sulfhydryl compounds GSH, GSSG, Cys and NPT increased by 53.2%, 164.2%, 53.9% and 0.79%, respectively, under high Cd concentration (200 mg/L), while the GSH/GSSG ratio decreased significantly. The study found that C. cristata L. seed germination period and seedling stage have a certain tolerance to Cd stress, but the high concentration Cd stress still leads to the reduction of antioxidant enzyme activities in the seedling part, the excessive accumulation of ROS, resulting in a deeper degree of membrane lipid peroxidation, the product MDA content gradually increased; Cd stress promotes a different increase in low molecular sulfhydryl compounds, but the GSH/GSSG ratio decreases and the incell Redox is inhibited, which causes the normal growth metabolism of seedlings was blocked and the biomass decreased continuously.