Objective To understand the source of the sense of gain in work among specialist nurses, so as to provide a reference for the use and management of specialist nurses. Methods Using phenomenological research method, 33 specialist nurses from 11 hospitals were selected for semi-structured interviews, and Colaizzi seven-step analysis method was used to analyze, induce and extract themes. Results Four themes and 12 subthemes on the source of the sense of gain in work among specialist nurses were extracted:the sense of gain in work reward （ability enhancement, development and promotion, salary incentive）, sense of gain in value identity （patient identification, occupational attribution, social recognition）, sense of gain in organizational support （hospital support, cultural shaping, management empowerment）, sense of self-transcendence （independent decision making, challenge and innovation, career expectation）. Conclusion Hospitals can stimulate specialist nurses′ sense of work gain through improving management system, strengthening professional identity, enhancing hospital support and access environment, and other optimization interventions, then enhance their work engagement, initiative and creativity, and finally realize the high-quality development of hospital specialist nursing team.