Based on the 2018 CLHLS data，this study employs non-conditional logistic regression and nonlinear Oaxaca-Blinder decomposition to analyze the difference in cognitive function of rural empty nesters with severe aging trends from the gender perspective. The study found that there was a significant gender difference in the cognitive function of rural empty-nesters，and the proportion and score of normal cognitive function in rural female empty-nesters were significantly lower than that of males. Rural female empty-nesters showed sensitivity to marital status，loneliness and life satisfaction，while rural male empty-nesters showed sensitivity to self-rated economy. The cognitive difference of rural empty-nesters is 64.05% related to gender itself. The individual differences in education level，marital status，age，activity of daily living and social participation expand this gender difference in cognitive function of rural empty-nesters. This paper suggested providing relevant support，including improving the accessibility of medical services，and promoting social interaction activities to narrow the gender gap in cognitive function of rural empty-nesters，therefore better maintaining the health of older adults.