ObjectiveTo understand healthcareassociated infection(HAI) in group burn/trauma patients, and explore its risk factors.MethodsHAI occurred among 25 hospitalized patients with group burn/trauma during a bus deflagration event on May 12, 2014 were monitored and analyzed.ResultsOf 25 burn/trauma patients, 7 developed 10 times of HAI, incidence and case incidence of HAI were 28.00% and 40.00% respectively; the main infection sites were wound and lower respiratory tract, accounting for 60.00% and 30.00% respectively. 30 strains of pathogens were isolated from 7 patients with HAI, including  16 strains (53.34%) of gramnegative bacteria, 13 strains（43.33%） of grampositive bacteria, and 1 fungus (3.33% ). Risk factors for HAI were large burned area, high degree of inhalation injury, arteriovenous catheterization, urinary tract catheterization, tracheotomy, use of ventilator, and surgery.ConclusionIncidence of HAI is high in the group burn/trauma patients, corresponding intervention measures should be formulated according to the risk factors, so as to reduce the occurrence of HAI.