Objective: To analyze the mediating effects of loneliness and depressive symptoms on family functioning and life satisfaction among rural elderly patients with chronic diseases, so as to provide the basis for improving the life satisfaction of this population. Methods: Rural elderly patients with chronic diseases aged ≥60 years in Qiannan Buyi and Miao Autonomous Prefecture, Guizhou Province were selected using a multi-stage stratified random cluster sampling method from June to September 2022. Basic information such as gender, age, and chronic diseases were collected. Family function, life satisfaction, loneliness and depressive symptoms were evaluated using Family Care Index Scale, the Satisfaction with Life Scale, the b-item Revised VCLA Loneliness Sale and the 15-item Geriatric Depression Scale, respectively. The structural equation model was constructed using Amos software to analyze the mediating effects of loneliness and depressive symptoms on the relationship between family function and life satisfaction. The Bootstrap method was employed to test the mediating effects. Results: A total of 1 145 rural elderly patients with chronic diseases were recruited, including 517 males (45.15%) and 628 females (54.85%). Among the participants, 657 individuals (57.38%) were aged 60-<71 years, and 540 individuals (47.16%) had three or more chronic diseases. The scores for family function, life satisfaction, loneliness, and depressive symptoms were (3.90±1.18), (18.88±5.25), (12.88±2.99), and (6.65±2.26), respectively. Mediating effect analysis showed that family function had a direct positive effect on life satisfaction (β=0.179, 95%CI: 0.126-0.231). It also indirectly positively influenced the life satisfaction of rural elderly patients with chronic diseases through the independent mediating effect of depressive symptoms (β=0.035, 95%CI: 0.021-0.054) and the chained mediating effect of loneliness and depressive symptoms (β=0.021, 95%CI: 0.013-0.030). The mediating effect of depressive symptoms accounted for 14.89% of the total effect, while the chained mediating effect of loneliness and depressive symptoms accounted for 8.94% of the total effect. Conclusion Good family function can directly enhance the life satisfaction of rural elderly patients with chronic diseases and can also indirectly improve their life satisfaction by reducing loneliness and depressive symptoms.