Objective To understand the cognition on tuberculosis (TB) and its influencing factors among health care workers (HCWs) in medical institutions (MIs) in Gansu Province, and to provide a basis for improving HCWs' awareness on tuberculosis prevention and control. Methods Questionnaire about HCWs' cognition status on TB in MIs in Gansu Province was designed. HCWs' cognition status on TB in MIs in Gansu Province was surveyed through "Questionnaire Star", and influencing factors for HCWs' cognition on TB was analyzed statistically. Results A total of 60 636 valid questionnaires were collected. Among the surveyed HCWs, women accounted for 78.89%. 39.64% HCWs were aged 30-39 years. Nursing staff accounted for 53.05%. 57 440 (94.73%) HCWs got qualified score on cognition on TB (total score ≥14 points), 3 196 was unqualified (total score ≤13 points), accounting for 5.27%. Univariate analysis results showed that there were statistically significant differences in HCWs' cognitive qualification rate on TB in terms of hospital level and type, whether there were infectious disease department, gender, age, nationality, educational background, professionaity, professional title, years of work experience, and the number of times participating in occupational protection training (all P < 0.05). Conclusion There are multiple factors that influence HCWs' cognition on TB in Gansu Province. HCWs' cognition on TB can be improved by increasing the frequency of TB prevention and control knowledge training, improving HCWs' academic qualification, and strengthening the learning of relevant professional knowledge.