Abstract: OBJECTIVE To investigate risk factors and prevention of respiratory tract deep fungal infection in patients with diabetes mellitus, so as to determine the risk factors for respiratory tract infection and strengthen prevention. METHODS A total of 500 cases of infected patients with diabetes mellitus from Dec. 2013 to Sep. 2015 were randomly selected as research objects. The pathogenic bacteria of respiratory tract deep fungal infection were analyzed, the risk factors of the infection were also investigated, and the data were analyzed by SPSS 16.0. RESULTS Totally 200 cases of respiratory tract deep fungal infection occurred in 500 cases of patients, with the infection rate of 40.00%, Totally 200 strains of fungi were detected, and mainly was 91 strains of Candida albicans, accounting for 45.50%. The results of multivariate analysis indicated that age, length of hospital stay, duration, the use of antimicrobial drugs, complications, blood glucose control level, and invasive operation were independent risk factors for respiratory tract deep fungi infection (P＜0.05). CONCLUSION The respiratory deep infected fungi infection rate is high during diabetes treatment in patients, and there are many risk factors for fungal infections. In order to reduce the incidence of infections, It is needed to strengthen the control and prevention of risk factors of respiratory tract deep fungus infection in diabetic patients.