Objective To understand the feelings and experiences of sense of security at work among clinical nurses, and to provide reference for targeted intervention. Methods A one-to-one, semi-structured interview was conducted among 15 clinical nurses in terms of their sense of security at work, then data were analyzed with Colaizzi′s method of phenomenological analysis. Results Four themes were identified: lack of security at work; strong sense of security at work; lack of safety support sources; and ineffective safety coping styles. Conclusion Clinical nurses experience sense of security at work. Hospital managers should pay attention to and provide targeted intervention to enhance safety of clinical environment.