Objective To explore the effect game-based cognitive intervention on mild cognitive impairment in type 2 diabetes mellitus (T2DM) patients. Methods A total of 60 T2DM patients developing mild cognitive impairment were evenly divided into a control group, who received routine nursing care for diabetes mellitus, and an intervention group, who were subjected to game-based cognitive intervention, which included blood sugar style checkers, recognition and recall of pictures, associative learning and reciting of paired phrases, grouping and arranging the orders of poker cards, game of the opposite, and keeping diaries. Results After the intervention, there were significant differences in MoCA scores, ADL scores and hypoglycemia knowledge scores, fasting glucose, 2h post-prandial glucose, and HbA1c between the 2 groups, with all the effect measures favoring the intervention group （P<0.05,P<0.01）. Patient satisfaction rate with nursing service in the intervention group was 93.33%, significantly higher than 73.33% of the control group（P<0.05）. Conclusion Game-based cognitive intervention could enhance the cognitive function of T2DM patients developing mild cognitive impairment, improve the effect of clinical therapy, and patient satisfaction with nursing service.