Hospital outpatient rooms are characterized by high pedestrian flow， high viral load， poor patient immunity， and frequent close contact between doctors and patients， making them a high-risk site for the transmission of respiratory infections. In this study， we first described the behavioral characteristics of patients and doctors during outpatient visits and assessed the risk of cross-infection through questionnaires and on-site research in outpatient rooms of two third-class hospitals in Changsha， followed by experimental tests and CFD simulations to reveal the dispersion pattern of exhaled flow from patients， and finally explored the effectiveness of current prevention and control measures. The results of the questionnaire and on-site research showed that there were many loopholes in prevention and control in outpatient rooms， i.e. windows and air conditioning were not always open， ventilation was poor， there were no purifiers in the room， disinfectant was used less frequently， and there were high-risk behaviors such as removing masks and physical contact. The research found that one doctor in the outpatient room treated up to 70 patients a day， the average length of a patient's visit was around 6~13 minutes， the number of people inside the room could reach up to 6~8， and was often accompanied by people walking around， which tended to accelerate the spread of exhaled flow， so it was necessary to strictly limit the number of people entering the room. Experimental tests and simulations showed significant differences between the trajectories and peak concentrations of exhaled flow from different people， demonstrating the complex nature of human sources. Exhalation patterns have a small effect on peak concentrations throughout， but breathing and speaking can result in high concentrations being maintained in front of the face for long periods. Wearing a mask significantly reduces the horizontal dispersion of pollutants， but causes an increase in dispersion distance in the vertical direction. The results of this study are expected to provide basic information for proposing and improving prevention and control measures in outpatient rooms.