Template-based approach has been widely applied in the modeling of multi-body dynamics system and its effectiveness is proven for the large and complex systems. However, issues like interoperability and scalability hinder the further applications. This paper presents a tool to support template-based modeling of multi-body system with improved capability for easy template creation, modification and translation.In our approach, the data and algorithms are capsulated in templates represented with class concept in open-source language Python. With the hierarchical definition of classes at different levels such as model, sub-system and components, the modeling complexity of large models are greatly reduced and fast model creation and modification are enabled to support the high level simulations and optimizations. This modeling practice has been successfully applied in the modeling of tracked vehicle, military trucks and other large systems with improved effectiveness and efficiency.