Abstract: The water consumption in the mineral processing is huge, and the efficient treatment of mineral processing wastewater is of great significance for the sustainable development of mines. Chitosan is a cationic linear polymer polysaccharide obtained by deacetylation of chitin, which has the advantages of low cost, non-toxicity and biodegradability, and is considered to be the most promising green natural flocculant. However, the small molecular weight and poor solubility of chitosan limit its application. Chemical modification of chitosan can improve its related physical and chemical properties, among which graft copolymerization is an effective method to improve the water solubility and flocculation performance of chitosan. To develop green and efficient chitosan-based flocculants to improve the treatment efficiency of mineral processing wastewater, in this paper, based on the molecular dynamics simulation method, different types of chitosan graft copolymers were first constructed, including non-ionic chitosan grafted polyacrylamide (Chi-g-PAM), cationic chitosan grafted acrylamide- dimethyl diallyl ammonium chloride (Chi-g-P(AM-DMDAAC)), and anionic carboxymethyl chitosan grafted polyacrylamide (CMC-g-PAM). By calculating the solvation free energy ( ), radius of gyration ( ), mean square displacement (MSD), and diffusion coefficient (D), the influence of graft monomer type on the solubility of chitosan graft copolymers was systematically analyzed. Specifically, the , , MSD, and D of the ionic flocculants CMC-g-PAM and Chi-g-P(AM-DMDAAC) were much larger than those of the non-ionic flocculant Chi-g-PAM. The results indicated that compared with non-ionic flocculants, the ionization of ionic flocculants increased the interaction force between the flocculant molecules and water molecules and generated electrostatic repulsion between polymer chains, resulting in greater chain extension and better solubility. Secondly, the cationic Chi-g-P(AM-DMDAAC) with good water solubility was selected as the research object. The adsorption capacity of Chi-g-P(AM-DMDAAC) was characterized by interaction energy ( ), while its bridging ability was evaluated through solvent accessible surface area (SASA), , MSD, D and adsorption conformation. The influence of the number and length of branched chains on the flocculation performance of chitosan graft copolymers was analyzed in detail. The results showed that as the number and length of branched chains of chitosan increased from 2/3 to 6/9, the , SASA, MSD, and D values increased. Concurrently, the adsorption conformation evolved from a "train-like" mode to a configuration in which one end of the flocculant was firmly adsorbed onto the kaolinite surface while the other end extended fully into the aqueous phase. This extended conformation facilitated effective bridging between kaolinite particles, resulting in optimal flocculation performance under these conditions. When the number of branched chains continued to increase while the length of branched chains decreased, the , SASA, MSD, and D values decreased, and both the adsorption capacity and bridging ability were weakened. The flocculation sedimentation verification test of the simulation results confirmed that the flocculation performance was the strongest when the synthesized flocculant had many and long branched chains, which was consistent with the simulation results. This study provided an important research basis for the development of green and efficient chitosan-based flocculants and continues to play a guiding role in the selection of flocculants for mineral processing wastewater.