Objective To analyze the monitoring of healthcare-associated infection (HAI) in the intensive care unit (ICU) over the past 12 years based on Joinpoint regression model, and evaluate the trend changes and relevant factors of HAI incidence. Methods ICU patients in a tertiary first-class hospital from January 2012 to December 2023 were selected and performed prospective monitoring. Trend changes of HAI incidence and the correlation with consumption of hand hygiene products as well as HAI management measures were analyzed. Results From 2012 to 2023, 6 929 ICU patients were included in the monitoring, 543 patients had 655 episodes of HAI, with incidence and case incidence of HAI being 7.84% and 9.45%, respectively. The average severity of the disease was 3.62, and the adjusted HAI incidence was 2.17%. The daily incidence of ventilator-associated pneumonia (VAP), catheter-associated urinary tract infection (CAUTI), and central line-associated bloodstream infection (CLABSI) were 6.19‰, 3.45‰, and 1.23‰, respectively. The consumption of hand hygiene products was 122.98 mL/bed-day. The compliance rate and correct rate of hand hygiene were 90.63% and 90.46%, respectively. From 2012 to 2023, incidence of HAI (51.29% vs 4.39%), case incidence of HAI (72.41% vs 4.94%), the adjusted incidence of HAI (15.98% vs 1.04%), daily incidence of VAP (22.50‰ vs 4.33‰), daily incidence of CAUTI (14.23‰ vs 1.64‰), and daily incidence of CLABSI (10.60‰ vs 0.20‰) all decreased significantly (all P<0.05). Both consumption of hand hygiene products (75.16 mL/bed-day vs 147.35 mL/bed-day) and correct rate of hand hygiene (85.00% vs 90.28%) increased significantly (both P<0.05). A total of 1 946 pathogens were detected, with an increase in the proportion of Staphylococcus aureus (1.30% vs 9.57%) and a decrease in the proportion of fungi (11.04% vs 1.74%). The daily consumption of hand hygiene products negatively correlated with the incidence of HAI, the case incidence of HAI, as well as the daily incidence of CAUTI and CLABSI (all P<0.05). Incorporating HAI real-time monitoring system and HAI management into performance assessment could decrease HAI-rela-ted incidence (P<0.05). Conclusion HAI-related incidence presents a downward trend. Scientific and comprehensive HAI prevention and control management measures such as healthcare workers’ hand hygiene management, online HAI real-time monitoring system, and incorporating HAI management into performance assessment can decrease HAI-related incidence and promote the improvement of medical quality.