Objective To analyze the influencing factors and gender differences of cognitive function among empty-nesters in rural areas of China, and to provide reference for reducing the differences in cognitive function among the elderly. Methods Unconditional logistic regression and nonlinear Oaxaca-Blinder decomposition were used to analyze the data of 3467 elderly people aged 60 and above from Chinese Longitudinal Healthy Longevity Survey (CLHLS 2018) to study the status and differences of cognitive function. Results The female normal cognitive function ratio was 76.73% (1253/1633), while male was 87.30% (1601/1834), with significant difference (X2^=66.254, P<0.001). The nonlinear Oaxaca-Blinder decomposition showed that the differences in cognitive function between different gender was 63.39% related to gender differences themselves, and 36.61% related to characteristics. Conclusion The cognitive function of rural female empty-nesters is lower than that of male. Measures such as improving the availability of medical services and providing social interaction activities can be taken to reduce the difference in cognitive function.