Objective To explore the effects of standardized environmental enrichment (EE) on cognitive function and serum brain-derived neurotrophic factor (BDNF) levels in patients with post-stroke dementia. Methods A prospective study was conducted, including 80 patients with post-stroke dementia admitted to Department of Traditional Chinese Medicine Rehabilitation, 910th Hospital of the Joint Logistics Support Force of Chinese PLA from January 2021 to May 2023. Patients were randomly divided into control group, cognitive training (COG) group, aerobic exercise training (AE) group and environmental enrichment (EE) group, with 20 cases in each group. All patients received routine treatment, with COG group receiving additional cognitive function training (30 minutes each time), AE group receiving additional aerobic exercise training (30 minutes each time), and EE group receiving both aerobic exercise and cognitive function training (15 minutes of aerobic exercise training and 15 minutes of cognitive training each time). The training was conducted once a day, 5 days a week, for a total of 8 weeks. The patients' mini-mental state scale (MMSE), modified Barthel index (MBI), Hamilton depression scale (HAMD), stroke-specific quality of life (SS-QOL) score and serum levels of BDNF were assessed before treatment, at 4 weeks and 8 weeks of treatment, respectively. Results Before treatment, there were no significant differences in general information, MMSE, MBI, HAMD, SS-QOL scores, and serum levels of BDNF among the four groups (P>0.05). After 4 and 8 weeks of treatment, the above indicators of the four groups were improved compared with those before treatment, with all differences being statistically significant (P<0.05). Inter-group comparison showed that after 4 and 8 weeks of treatment, MMSE, MBI, SS-QOL scores, and serum BDNF levels in COG, AE and EE groups were significantly higher than those in control group, and HAMD scores were significantly lower than those in control group (P<0.05). In addition, MMSE, MBI, SS-QOL scores and BDNF levels of group EE were better than those of other 3 groups, while HAMD scores were lower than those of other 3 groups, with all differences being statistically significant (P<0.05). There was no significant difference in above outcome indicators between COG group and AE group after 4 and 8 weeks of treatment (P>0.05). Conclusion Standardized enrichment environment can significantly enhance cognitive function, daily living abilities of post-stroke dementia patients, alleviate depression symptoms, and improve the quality of life, which may be related to the increase in serum BDNF levels.