Solid geometry is the emphasis and the difficulty in high school mathematical teaching. This paper described the design and implementation, Dragon 3D Sketchpad, a solid geometry intelligent educational platform for assisting the teaching and learning of solid geometry. It was a dynamic solid geometry software and had the ability of automated geometry reasoning, it could generate short and readable proofs in traditional style. We gave the idea and explained the design and elementary functions of the platform and some cases to demonstrate this intelligent educational platform were shown.