Objective To understand the current rate of nosocomial infection and its changing trend in a grade A comprehensive hospital in 10 years, and to provide scientific basis for the monitoring, control and management of nosocomial infection. Methods Using the method of cross-sectional survey, the inpatients in Mianyang Central Hospital from 2011 to 2020 were selected for bedside survey, and the questionnaire was filled in after review of medical records. The data of cross-sectional survey of nosocomial infection were collected, and the infection-related data of nosocomial and community-acquired infection of patients in each department were statistically analyzed. Results A total of 19 595 cases were investigated. The prevalence rate of nosocomial infection was 3.79%, and the the case prevalence rate of nosocomial infection was 4.04%. The prevalence of community-acquired infection was 33.44%, and the case prevalence rate of community-acquired infection was 35.30%. The departments with higher prevalence rate in nosocomial infection were intensive care unit, neurosurgery, cardiothoracic surgery and hematology. The departments with high prevalence rate in the community-acquired infection were burn department, pediatrics department, neonatology department, respiratory medicine department and pediatric intensive care unit. The most common site of nosocomial infection was lower respiratory tract infection, followed by upper respiratory tract sensation, urinary tract, abdominal tissue and blood. The main pathogens of nosocomial infections were Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Staphylococcus aureus, and Pseudomonas aeruginosa. The utilization rate of antibacterial drugs was 42.93%. There was a downward trend in prophylactic drug use, mainly one drug combination, and the proportion of combination drug decreased.Conclusion Through the investigation, it can be seen that the key points of nosocomial infection management and prevention and control should be lower respiratory tract infection, postoperative surgical infection, multi-drug resistant bacteria management and rational use of antibiotics.