Objective To investigate the effects of dictyophora polysaccharides（DIP） on cognitive dysfunction induced by chronic alcohol exposure in rats. Methods Sixty male Sprague-Dawley（SD） rats were randomly divided into five groups（n=12）：control group （normal saline），DIP group［DIP_H，DIP administered by gavage at 300 mg/（kg·d） for 28 consecutive days］，alcohol group［EtOH，60% alcohol administered by gavage at 10 mg/（kg·d） for 28 consecutive days］，low-dose DIP treatment group［EtOH+DIP_L，60% alcohol administered at 10 mg/（kg·d） and DIP administered at 100 mg/（kg·d） by gavage，with an interval of 6 hours between doses，for 28 consecutive days］，and high-dose DIP treatment group［EtOH+DIP_H，60% alcohol administered at 10 mg/（kg·d） and DIP administered at 300 mg/（kg·d） by gavage，with an interval of 6 hours between doses，for 28 consecutive days］. On day 25 of gavage，water maze training was provided for the rats for 4 days. On day 29，a water maze test was performed to determine the memory and learning functions of the rats；HE staining was used to evaluate the edema and inflammation of the liver and brain tissues； presence of inflammatory cells and the expression of myelin basic protein（MBP） in brain tissue were measured using immunohistochemical staining； Western blot was used to measure the expression of 2，2-cyclic nucleotide-3-phosphodiesterase（CNP） in the hippocampal tissue；the structural integrity of the myelin sheath was evaluated using LuxoL fast blue（LFB） staining and transmission electron microscopy. Results Compared with the control group，the EtOH group showed a significantly increased escape latency，reduced expression of MBP，and decreased density of the myelin sheath. DIP intervention significantly improved cognitive dysfunction in rats，increased the expression of MBP and CNP，and reduced myelin damage. Conclusion At a dose of 300 mg/kg，DIP may ameliorate cognitive dysfunction induced by chronic alcohol exposure by protecting the structural and functional integrity of myelin sheaths.