Objective To understand status of protection behavior and protection knowledge level of accompanying visitors of hospitalized patients during the epidemic period of coronavirus disease 2019 (COVID-19). Methods Convenient sampling method was adopted to select accompanying visitors of non-confirmed or suspected COVID-19 patients in departments of oncology, respiratory, hematology, and orthopedics of a tertiary first-class hospital from February 3 to February 6, 2020 as studied subjects. Phenomenological research method and self-designed questionnaire about prevention and control knowledge were used for survey. Results A total of 208 questionnaires were sent out, and effective respond rate was 100%. Direct observation of researchers showed that implementation rate and correct rate of wearing masks were 84.62% (176/208) and 50.57% (89/176) respectively. Implementation rate and correct rate of hand hygiene were 75.00% (156/208) and 22.44% (35/156) respectively. Implementation rate of ward ventilation was 100%, 90.38% of the accompanying visitors ventilated wards twice a day. Questionnaire of protection knowledge level showed that accompanying visitors had the highest correct rate in knowing clinical manifestations of COVID-19, which was 98.08%; only 50.48% of accompanying visitors thought that novel coronavirus (2019-nCoV) could be killed by 75% alcohol; 46.15% of accompanying visitors thought it was necessary to inform medical staff of their temperature rise; 8 accompanying visitors thought they could get together to chat with friends and relatives. Conclusion The correct implementation rate of protection behavior of accompanying visitors is low, education on COVID-19 prevention and control knowledge and behavior among accompanying visitors should be emphasized in ward area, so as to improve correct implementation rate of protection behavior, and avoid the occurrence of hospital clustering epidemic.