To analyze the relationship between social inclusion and cognitive function of older adults in China and provide a theoretical basis for future research on reducing the risk of cognitive impairment in older adults through social inclusion interventions.

Data were collected from the China Health and Retirement Longitudinal Study (CHARLS) in 2015 (T1), 2018 (T2), and 2020 (T3), which measured cognitive function and social inclusion (economic inclusion, relational inclusion, and community inclusion) of 5 464 elderly people aged of and above 60. A cross-lagged model was adopted to analyze the effect of social inclusion on changes in cognitive function of older adults from T1 to T3.

The 5 464 people aged of and above 60 included in the analysis showed the total cognitive function scores of (14.11 ± 5.26), (12.55 ± 6.17), and (12.14 ± 5.99) and total social inclusion scores of (2.15 ± 1.06), (1.73 ± 0.85), and (1.64 ± 0.87) in T1, T2, and T3 periods, respectively. After the control of confounding factors such as sex, age, and education, the total social inclusion scores in T1 and T2 could positively predict the total cognitive function scores in T2 and T3 (β′ = 0.019 and 0.017, both P < 0.01), respectively. The community inclusion scores in T1 and T2 could positively predict the total cognitive function scores in T2 and T3 (β′ = 0.016 and 0.016, both P < 0.05), respectively. The total cognitive function score in T1 could positively predict the total social inclusion score, economic inclusion score, relational inclusion score, and community inclusion score (β′ = 0.051, 0.023, 0.025, and 0.057, all P < 0.05) in T2. The total cognitive function score in T2 could positively predict the total social inclusion score, economic inclusion score, relational inclusion score, and community inclusion score (β′ = 0.063. 0.031, 0.027, and 0.075, all P < 0.05) in T3.

Good social inclusion of older adults can protect their cognitive function, especially community inclusion, and good cognitive function of older adults can promote social inclusion.