Explore the cutting-edge field of 3D spatial intelligence in this comprehensive conference talk delivered at ICBS2025. Delve into the fundamental concepts, methodologies, and applications of spatial reasoning in three-dimensional environments, examining how artificial intelligence systems can understand, process, and interact with 3D spatial data. Learn about the latest research developments in computer vision, robotics, and machine learning as they relate to spatial cognition and 3D scene understanding. Discover how 3D spatial intelligence is revolutionizing fields such as autonomous navigation, augmented reality, robotics manipulation, and spatial computing. Gain insights into the challenges and opportunities in developing AI systems that can effectively perceive, reason about, and operate within complex three-dimensional spaces, while understanding the implications for future technological advancement in spatial AI applications.