Background: The current study examined the interrelations among social support, family quality of life (FQOL), and family cohesion and adaptability in Chinese families of children with autism spectrum disorder (ASD). Methods: A sample of 163 caregivers of children with ASD in China were surveyed with the Social Support Rating Scale, Beach Center Family Quality of Life Scale, and Chinese version of Family Adaptability and Cohesion Scale II, respectively. We used structural equation modeling to examine the mediating role of family cohesion and adaptability on the relationship between social support and FQOL. Results: The results indicated that social support had a positive impact on FQOL and that family cohesion and adaptability completely mediated the relationship between social support and caregivers' satisfaction on FQOL. Conclusions: Facilitating family cohesion and adaptability by providing social support may be beneficial to help families of children with ASD improve their FQOL. The findings identified the need for developing targeted interventions for this population.