Nosocomial infection (NI) harms patients' health. Timely identifying the high-risk groups of NIs plays a vital role in preventing and control of NIs. Therefore, it is crucial to investigate whether the ABO blood group is a risk factor for NI to identify and protect high-risk populations. In this study, the patients of NI and non-infection from January 2016 to July 2022 were matched by the propensity score matching (PSM) method and analysed stratified by NI pathogens and NI sites. Finally, a logistic regression model was used to analyse the matched datasets. The study found that: Patients with the B&AB blood group were susceptible to Escherichia coli (OR=1.783, P=0.039), patients with the A blood group were susceptible to Staphylococcus aureus (OR=2.539, P=0.019), and Pseudomonas aeruginosa (OR=5.724, P=0.003). Patients with the A&AB blood group were susceptible to Pseudomonas aeruginosa (OR=4.061, P=0.008). Patients with the AB blood group were vulnerable to urinary tract infection (OR=13.672, P=0.019), patients with the B blood group were susceptible to skin and soft tissue infection (OR=2.418, P=0.016), and patients with the B&AB blood group were vulnerable to deep incision infection (OR=4.243, P=0.043). Summarily, The patient's blood group is a susceptibility factor for common NI pathogens and NI sites, which is vital for identifying high-risk groups for NIs and developing targeted prevention and control measures for NIs.