Objective To develop a theoretical framework for emergency preparedness of nursing interns for public health emergencies. Methods Nursing interns and clinical instructors with experience of public health emergencies participated in semi-structured interviews. Interview data were coded at three levels using the Straussian grounded theory approach and Nvivo 12 software. Results A total of 53 beginning categories, 9 major categories, and 3 core categories (attitude toward emergencies, professional preparedness for emergencies, and support availability) were identified. Conclusion The established theoretical framework can be used for emergency preparedness cultivation of nursing interns for public health emergencies, so as to improve their emergency preparedness.