Except for the high adsorption capacity, the color of the adsorbent suspension and the solid-liquid separation characteristics are also essential factors for adsorption material in wastewater management. Here, a novel carboxymethyl chitosan grafted magnetic montmorillonite (CMC@MMt) adsorbent-material with large metal ions uptake capacity, transparent solution, excellent turbidity, and low cytotoxicity in human hepatic cells (HepG2 cells) was successfully synthesized by plasma technology. The adsorption performance for different metal ions, the turbidity property, and the toxicity of CMC@MMt were evaluated by systematic studies. The results indicate that adding of CMC could enhance the adsorption capacity because of NH2, COOH, and OH functional groups. Especially the turbidity property of montmorillonite was also improved due to the enlarged grain size and the polarity reduction. This research will promote the application of clay mineral-based material in environmental pollution control, such as preconcentration and immobilization of heavy metal ions.