The long-term care insurance (LTCI) system has become a key policy tool for alleviating the care pressure on disabled elderly people in China and promoting the high-quality development of the health and elderly care industry. This study takes 154 elderly care listed companies in China's capital market as the research sample, and uses the difference-in-differences method to construct a quasi-natural experiment framework to systematically evaluate the impact of the LTCI policy on the financial performance of various elderly care industries, and verify the differentiated performance of the policy in different regions and sub-sectors. The research shows that the LTCI pilot policy has significantly improved the profitability of elderly care enterprises in the pilot areas, increasing the average ROA by 2.27 percentage points and ROE by 6.33 percentage points. The heterogeneity analysis indicates that the industrial driving effect, service innovation level, and financial improvement amplitude in economically developed regions are significantly higher than those in the central and western pilot areas. Among the sub-sectors, medical care services stand out, with ROA increasing by 4.17 percentage points. The research indicates that the LTCI policy mainly exerts its influence through the dual effects of demand pull and cost optimization. Technology-intensive elderly care enterprises and economically developed regions benefit more due to their inherent advantages. To some extent, this study enriches the quantitative research results on the impact of the LTCI system on the health and elderly care industry and provides practical references for policy optimization, industry development guidance, and enterprise operation decisions.