Objective To describe the level of professional identity of nursing students during a public health emergency and to analyze the influential factors. Methods In March 2020, 5 582 full-time vocational college and baccalaureate nursing students were surveyed using the Professional Identity Questionnaire and Connor-Davidson Resilience Scale-10. Results The total score of professional identity was 99.62±14.90. Multiple linear regression analysis indicated that whether being one child or not, education level, psychological resilience, and whether to undertake volunteer services or clinical care during COVID-19 public health emergency were the influencing factors of professional identity (P＜0.01 for all). Conclusion Professional identity of nursing students is at medium level and affected by several factors. Social position and professional honor of nurses have been improved since COVID-19 outbreak, so they contribute to nursing students′ professional identity. Targeted interventions should be formulated based on the influential factors in an effort to stabilize nursing students′ professional attitude and then improve their willingness to stay.