This study explores gender differences in the functional development of older adults in China, identifies the types and influencing factors of functional trajectories among older men and women, and provides a basis for formulating gender-sensitive health intervention strategies for the elderly. Using data from the China Health and Retirement Longitudinal Study (CHARLS) from 2011 to 2020, individuals aged 60 and above were selected as the study population. Group-based trajectory modeling (GBTM) was employed to identify the dynamic functional trajectories by gender, and multinomial logistic regression was used to analyze the influencing factors associated with membership in different trajectories. Significant gender differences were found in the functional development trajectories of older adults. Among men, the trajectories were classified as "stable and healthy," "low baseline–stable–then declining," "low baseline–rapidly increasing," and "high baseline–slowly increasing." Among women, the categories were "stable and healthy," "low baseline–declining–then stable," "low baseline–rapidly increasing," and "high baseline–slowly increasing." The proportion of women in the "stable and healthy" trajectory was lower than that of men. Demographic characteristics, lifestyle factors, and health status significantly influenced the likelihood of individuals entering different functional trajectories, and these influencing factors varied by gender. Given the evident gender-specific patterns and heterogeneity of functional development among older adults, it is essential to establish dynamic, gender-specific intervention mechanisms to advance precise and personalized elderly health management strategies.