Abstract: This paper addressed the demand for precise marketing decision-making in railway freight yards, and presented a design scheme of a data-driven marketing decision support system for railway freight yards. It aimed to provide intelligent decision support for production monitoring, marketing management, customer service and resource management by integrating multi-source internal and external data in freight yards, so as to improve the service quality and operation efficiency of railway freight transportation. This paper adopted multi-source heterogeneous data fusion technology and combined the Prophet time series prediction model, which realized the transformation of railway freight yard marketing modes from passive response to active prediction, and provided scientific, accurate and intelligent support for marketing decision-making. Practical applications show that the system not only verifies the applicability of data-driven technologies in the field of railway freight yards, but also provides a reusable technical path for the digital transformation of marketing management in railway freight yards.