This paper reviews corrosion big data technology and its applications in the intelligent engineering, in systematically. Corrosion serves as an essential factor, which threatening the service safety and service life of engineering materials. Corrosion data exhibits complicated characteristics, such as multi−source heterogeneity, long duration, cross−scale, and non−linearity. These characteristics, corrosion big data technology integrate various sensor technologies and establishing multi−dimensional intelligent correlation databases, which can support the mining and visualizing of material corrosion big data to achieving the construction of corrosion big data sharing platform and engineering applications services. In intelligent engineering applications, corrosion big data technology possesses three core functions. First, real−time monitoring technologies had been applied on recording the corrosion status of facilities such as bridge steel structures and oil−gas transmission pipeline sin dynamically, combined with high−throughput collection of multi−source heterogeneous corrosion data, to instantly record corrosion rates and environmental parameters for systematic data gathering; Analyzing the coupling laws between corrosion data, environmental factors, and operational conditions through multi−source data mining technology to support dynamic optimization of anti−corrosion strategies; Achieving precise prediction of the service life of engineering, based on artificial intelligence models (e.g., neural networks), combined with accumulated corrosion big data and machine learning algorithms, providing quantitative basis for engineering safety operation and maintenance. Furthermore, by integrating with digital twin technology, corrosion big data constructs a 3D virtual model of corrosion process to achieve visual warning of engineering maintenance status. The joint construction of corrosion big data sharing platforms is promoted and advancing the traditional anti−corrosion technology towards to closed−loop management system, "perception−diagnosis−decision−execution". Corrosion big data technology supports and promotes the intelligent and precise transformation of traditional anti−corrosion technologies, and support the safety operation and maintenance system of smart engineering, demonstrating broad application prospects in fields such as marine engineering and energy internet.