Taking the K Institution Elderly Care Center in Fuzhou City as a case, this study employs the analytical framework of the politics of care to argue that care is not merely a technical service operation, but a social practice involving the distribution of responsibility, negotiation of power, and ethical response. From this perspective, the research re-examines the institutional care process for older adults with dementia and finds that although medical staff, nursing attendants, family members, and social workers each undertake distinct caring roles, the uneven distribution of power weakens inter-subject collaboration and constrains improvements in overall care quality. Accordingly, this study highlights the crucial potential of social workers—given their unique strengths in communication, emotional support, and ethical advocacy—to facilitate the reconstruction of co-care practices. Looking forward, it is essential to further clarify the professional functions of social work, enabling social workers to play an integrative and empowering role in inter-professional collaboration within eldercare institutions. In doing so, institutional care for older adults with dementia can become more professionalized, humane, and oriented toward coordination, person-centeredness, and sustainability.