The invention relates to antibacterial chitosan gel and a preparation method of the antibacterial chitosan gel. The preparation method includes the steps of preparing complex liquid containing chitosan, preparing a fibroin ethanol solution, preparing a carrageenan solution, preparing a quaternary phosphonium compound solution, preparing gel and other steps. According to the antibacterial chitosan gel, high-molecular-weight chitosan and low-molecular-weight chitosan compounds are used as main base materials in cooperation with antibiotic synergist, gelatinizing agents, histocyte repairing auxiliary materials and the like for being compounded, and use of other chemicals, biological drugs and other ingredients is avoided; as a result, the safety of the gel is improved, cost is reduced, irritation to patients is reduced, and health restoration of the patients is facilitated. The ability of the prepared antibacterial chitosan gel to resist bacteria such as staphylococcus aureus, coliform bacteria, streptococcus and pseudomonas aeruginosa reaches more than 99 percent, so the antibacterial chitosan gel shows good bacteriostatic ability.