Caregivers of advanced cancer patients face challenges impacting their quality of life (QoL). While evidence suggests that family sense of coherence (FSOC) can enhance individual psychological well-being and reduce distress symptoms, the precise mechanism through which FSOC improves caregivers' QoL remains unclear. This study aimed to explore the relationships among FSOC, psychological resilience, psychological distress, and QoL in primary caregivers of advanced cancer patients. A cross-sectional observational study was undertaken from June 2020 to March 2021 across five tertiary hospitals in China. Instruments included a general characteristic questionnaire, the Family Sense of Coherence Scale, the Patient Health Questionnaire-4, the 10-item Connor-Davidson Resilience Scale, and the 8-item SF-8 health survey. Pearson's correlation and chain mediation analyses were performed using IBM SPSS (version 21) and PROCESS macro (version 3.4). Out of 290 valid questionnaires, results demonstrated that FSOC directly and positively influences caregivers' QoL. Psychological distress partially mediated the FSOC-QoL association, with paths "FSOC-psychological distress-QoL" and "FSOC-psychological resilience-psychological distress-QoL" contributing 43.08% and 6.72% of the total effect, respectively. Furthermore, this study distinguished physical and mental aspects of QoL, confirming both conform to the chain mediation model. FSOC impacts caregivers' QoL directly and indirectly through the mediation of psychological distress and the chain mediation effect of "psychological resilience-psychological distress". These insights enhance our understanding of the complex interplay between FSOC and QoL, underscoring the potential benefits of bolstering FSOC to strengthen caregiver resilience, alleviate distress, and ultimately elevate their QoL.