Objective To construct a cloud-based platform for healthcare-associated infection (HAI) management based on multi-source data fusion and data visualization, and evaluate its application effectiveness. Methods A tertiary first-class cancer hospital was selected as the research object. Aligned with graded hospital accreditation standards and based on grid-based management and responsibility zone mode, a platform was constructed in 2023 with low-code technology, multi-source data fusion, and visualization function. The self-comparison method was adopted to compare occurrence of HAI before and after the operation of the platform. A questionnaire survey was adopted to assess the experience and workload reduction feelings of full-time and part-time infection surveillance and control profe-ssionals using the platform. Results 81.56% of the surveyed respondents believed that the platform could reduce the workload of infection surveillance and control. Compared with before the trial operation, the hospital achieved an annual reduction of 11 200 yuan in paper costs, with associated labor savings of approximately 4 482.5 hours. The incidence of HAI cases in the whole hospital decreased from 0.67% to 0.45%. The pathogen detection rate before therapeutic use of antimicrobial agents increased from 51.26% to 71.54%. Differences were both statistically significant (both P < 0.05). The detection number and proportion of carbapenem-resistant Pseudomonas aeruginosa (CRPA) and extended-spectrum β-lactamase-producing Klebsiella pneumoniae (ESBL-KP) in HAI cases decreased (54.55% vs 36.47% and 51.14% vs 32.50%, respectively, both P < 0.05). Conclusion The construction and application of smart HAI management cloud-based platform can reduce cost, improve management quality, and provide a theoretical basis and technical paradigm for the construction of smart HAI management system.