Abstract: To effectively support workers engaged in manual material handling (MMH) tasks and reduce the risk of work-related musculoskeletal disorders (WMSDs), particularly low back pain (LBP), we systematically review the research status and key technologies of three types of lumbar assist exoskeletons: powered, unpowered, and quasi-passive. We identify each exoskeleton type's design characteristics and application suitability by analyzing mechanical structure, drive mechanisms, human-computer interaction, and comfort. The findings indicate that powered exoskeletons excel in assistance performance and human-machine coordination， unpowered exoskeletons offer a lightweight design suitable for short-term, low-load tasks, and quasi-passive exoskeletons strike a balance between moderate assistance and energy efficiency through energy recovery mechanisms. We highlight critical challenges in optimizing assistance performance and enhancing adaptability to human-machine interaction. Additionally, we propose design recommendations based on intelligent materials and advanced control strategies, providing both a theoretical foundation and practical guidance for the future development of lumbar assist exoskeletons.