Growth model-based decision support system is one of the important parts of digital farming techniques. Driven by soil, variety, weather and management databases, a growth model-based decision support system for rapeseed management(GMDSSRSM) was developed by integrating growth simulation technology and component-based software technology, including a stand-alone edition(GMDSSRSM^A) and a web-based edition(GMDSSRSM^W). The GMDSSRSM^A was established on the platforms of VC++ and VB by adopting the characteristics of object-oriented and component-based software and with effective integration and coupling of the growth prediction and decision-making functions for cultural management. Then, GMDSSRSM^W was further developed on the platform of .net with C# language for web users. The implemented systems with the characteristics of powerful mechanism, good prediction, fine adaptability and comprehensive function realized the functions of data management, prediction of growth dynamics, evaluation of individual and comprehensive management strategies, real time growth data based simulation, time and spatial analysis, sensitivity analysis, expert consultation, and system help. The GMDSSRSM is regarded as quantitative and digital tools for prediction of rapeseed growth and development and decision support. It may be useful for construction of digital farming system in modern rapeseed production.