A better understanding of the impact of lifestyle factors on cognitive function in older adults is critical for developing intervention strategies to achieve successful aging. Moreover, older adults who fulfill the World Health Organization criteria for anemia have a significantly higher risk of developing dementia. In the current study, we aimed to assess the buffering effects of lifestyle on cognitive function in older Chinese adults through a nationally representative survey. The sample consisted of 1201 participants (mean age: 82.39 +/- 12.08 years, 52.1% female) from the 2011/2012 and 2014 waves of the Chinese Longitudinal Healthy Longevity Survey. Multiple linear regression analyses were used to explore the relationship between changes in lifestyle factors and the rate of cognitive function changes, as well as the effects of the interaction between lifestyle factors and anemia on cognitive function changes. Increased levels of participation in leisure activities, social activities, and dietary diversity delayed cognitive decline. Persistent anemia accelerated cognitive decline, while frequent participation in leisure activities delayed cognitive decline due to anemia. The increased levels of participation in leisure activities, social activities, and dietary diversity can alleviate the cognitive decline caused by aging itself, and more frequently participation in leisure activities can also alleviate the adverse effects of anemia on cognitive function in older adults.