Objective To study the effect of on-site training during the epidemic period of COVID-19 on hospital staffs' self-protection knowledge and confidence against COVID-19, and to provide theoretical basis for reducing the infection of medical staff. Methods From January 30 to February 19, 2020, all of the 2 137 staffs who attended the on-site training were enrolled. A 9-item question test was taken before and after the on-site training to evaluate the training effect. A survey of current status of the staffs was done before the on-site training and a satisfaction of on-site training was investigated after the training to understand the satisfaction degree of on-site training. Results The pre-training survey show that 72.8%(1 556/2 137) of the staffs have not received training in wearing biosuit, 85.5% (1 827/2 137)had never worn biosuit, and only 16.8% (359/2 137) believed personal protection would be warranted if exposed to a confirmed case, 84.4% (1 804/2 137) of them thought an on-site training of personal protective knowledge was needed. Compared with pre-training test, the correct rate of all 9 items after training was improved, especially for hand hygiene, from 38.6% (825/2 137) before training to 73.3% (1 414/1 930) after training, the difference was statistically significant ( P<0.01). Vast majority of the participants considered it necessary to attend the on-site training and very satisfied with the training content and training arrangements. The training was consistent with their expectations and can increase their confidence to fight with COVID-19 . Conclusions On-line training is not enough to help the hospital staff doing self-protection during the epidemic period of COVID-19. It is necessary to organize on-site training under the condition of ensuring safety, systematic on-site training can improve the self-protection awareness and self-protection ability of hospital staff, and increase confidence in coping with COVID-19.