DIY exoskeleton legs are self-assembled lower limb mechanical support structures built by hobbyists, makers and engineering enthusiasts with common raw materials such as aluminum profiles, steel strips, hinge joints, tension springs and adjustable binding belts. Different from commercial powered rehabilitation or industrial exoskeletons, most homemade leg exoskeletons adopt passive mechanical design without motors, sensors or battery systems, relying on mechanical leverage and elastic components to share loads on knees and waists. Makers usually adjust leg length, hip width and joint rotation angles according to personal body size, designing limit structures to prevent over-bending during squatting, climbing or carrying heavy loads. These homemade devices can relieve fatigue during long walking, uphill hiking and frequent lifting tasks, and serve as experimental prototypes for learning bionic mechanics, structural stability and ergonomic design. However, DIY leg exoskeletons lack formal safety certification, precise load calibration and anti-fall protection mechanisms. Improper material selection or structural defects may lead to joint abrasion, structural fracture or secondary physical injury. Therefore, they are more suitable for technical research, personal trial use and small-load auxiliary scenarios rather than medical rehabilitation or high-intensity industrial working environments.