Abstarct: Abstract Today, one of the environmental concerns that exists is the entry of large amounts of chemical compounds such as heavy mextals into surface waters through urban areas and industries; heavy mextals enter the soil and food cycle from human activities and can cause poisoning. Environmental pollution, including soil pollution, is one of the important consequences of disrupting the balance of nature. The most important soil pollutants are heavy mextals, acid rain and organic matter. Various methods, including plant accumulation, biological and natural methods of cleaning and phytoremediation, are also used for cleaning. Currently, immobilizing heavy mextals in the environment through chemical stabilization is considered a suitable method for remediating contaminated soils due to its simplicity, effectiveness, applicability on site and low cost, and the main key to the method of immobilizing heavy mextals is the selection of an effective adsorbent. With the beginning of the 21st century, along with the role of biochar as a soil conditioner, interest and attention to the use of charcoal (biochar) in soil and the environment gained momentum among researchers in various fields. In this study, the removal of toxic mextals from soil by three adsorbents, sepiolite clay, sugarcane biochar, and clay-biochar complex, was investigated using the adsorption method. The aim of this study was to investigate and compare three adsorbents for the removal of heavy mextals. In order to characterize these three adsorbents, FTIR, SEM, and BET methods were used. The results show that the sepiolite clay-biochar complex reduces the exchangeable and carbonate forms of heavy mextals cadmium and nickel at a level of 2% compared to 0% and compared to the separate use of clay and biochar. This has resulted in less mobility of heavy mextals and more heavy elements are absorbed into the soil and pollution is reduced. Biochar has increased the iron-aluminum oxide form of nickel and cadmium mextals at 1 and 2 percent levels compared to the zero percent level, and this increase is greater at the 2 percent level than at the 1 percent level. Sepiolite clay reduces the concentration of the organic form of heavy mextals in the soil compared to biochar and the clay-biochar complex at the 2 percent level, which causes greater mobility and contamination. On the other hand, biochar at the 1 percent and 2 percent levels increases the organic form of nickel and cadmium compared to the zero percent level, and biochar is an effective adsorbent. The use of biochar at the 2 percent and 1 percent levels has reduced the residual concentration of nickel and cadmium, and the heavy mextal mobility and contamination are greater. The clay-biochar complex has had a greater effect on increasing the residual form of heavy mextals, which is observed at the 2 percent and 1 percent levels compared to the zero percent level. Therefore, the clay-biochar complex is a suitable adsorbent for absorbing heavy mextals.