Background The lack of adequate medical care, healthcare, and older adult care in remote, low-income, rural Kazakh areas of China is a particular concern that should be prioritized for improvement. Purpose This study was designed to explore the relationship between the variables of disability severity, social support, and caregiver competence and the quality of home-based care in a population of Kazakh older adults with disabilities and to analyze the path between severity of disability and quality of home-based care in this population. Methods A cross-sectional survey was conducted on 335 Kazakh older adults with disabilities living in Xinjiang, China, and their primary informal caregivers. Disability severity was assessed using the Activities of Daily Living Scale, caregiver competence was assessed using the Family Caregiver Task Inventory, social support was assessed using the Social Support Rating Scale, and home-based care quality was assessed using the Family Caregiving Consequences Inventory Scale. Path analysis was used to check the effects of other variables on the quality of home-based care. Results Significant correlations were found among disability severity, caregiver competence, social support, and home-based care quality. Disability severity was shown to have a 29.28% direct effect on home-based care quality and a 70.72% indirect effect through social support and caregiver competence. Conclusions The results of this study confirm that better social support and caregiver competence improves the quality of home-based care available to older adults with disabilities. Policymakers should give priority to improving the quality of care provided to community-dwelling older adults with severe disabilities. Furthermore, health management departments should provide informal caregiver training that teaches care and rehabilitation knowledge and skills to improve the competencies of caregivers.