WonderWorld is an innovative 3D scene expansion framework that allows users to explore and shape virtual environments based on a single input image and user-specified text. Through fast Gaussian voxel and guided diffusion depth estimation methods, it significantly reduces computing time and generates geometry-consistent expansions, resulting in 3D scene generation times of less than 10 seconds. It supports real-time user interaction and exploration. This opens up possibilities for rapidly generating and navigating immersive virtual worlds in fields like virtual reality, gaming, and creative design.