As artificial intelligence (AI) advances, 3D spatial computing has emerged as a key application in various fields. It interprets the 3D space surrounding users and provides them with useful information. This paper presents a survey of AI hardware architectures and silicon solutions for 3D spatial computing systems. The survey categorizes five domains: 3D data capturing, 3D data analysis, 3D hand motion analysis, simultaneous localization and mapping (SLAM), and 3D rendering. Each session analyzes design considerations for domain-specific accelerators. Finally, the paper discusses a next-generation 3D spatial computing platform that integrates various functions of 3D spatial computing systems using AI technologies.