Objective To identify the key influencing factors of death anxiety in rural elderly and their mechanisms of action. Methods A total of 701 rural elderly individuals from 6 prefecture-level cities (prefectures) in Sichuan Province were selected for a questionnaire survey on death anxiety, health-related physical fitness, and subjective well-being. A structural equation model was constructed to thoroughly analyze the influencing factors of death anxiety and their mechanisms of action. Results Higher levels of health-related physical fitness, higher levels of subjective well-being, and having more children were the top three protective factors against death anxiety among elderly people in rural Sichuan, with effect values of −0.392, −0.287, and −0.154, respectively. In contrast, suffering from chronic diseases was the leading risk factor for death anxiety, with an effect value of 0.127. Suffering from chronic diseases was the leading risk factor for death anxiety, with an effect value of 0.127. The structural equation model fitting results showed that the medical insurance type of rural elderly in Sichuan (β=−0.062, P=0.002), suffering from chronic diseases (β=0.127, P=0.001), hospitalization due to health reasons in the past year (β=0.086, P=0.002), and educational level (β=−0.067, P=0.001) had indirect effects on death anxiety through health-related physical fitness. Not seeking medical treatment due to financial difficulties in the past year had an indirect effect on death anxiety through subjective well-being (β=0.060, P=0.002). The number of children had both a direct effect on death anxiety (β=−0.119, P=0.004) and an indirect effect through subjective well-being (β=−0.034, P=0.001). Health-related physical fitness had both a direct effect on death anxiety (β=−0.278, P=0.001) and an indirect effect through subjective well-being (β=−0.114, P=0.002). Conclusion Multiple factors directly or indirectly affect the level of death anxiety in the rural elderly population. Health-related physical fitness, subjective well-being, and the number of children are important protective factors. Moreover, health-related physical fitness and subjective well-being act as mediating variables in the chain of effects of multiple factors on death anxiety.