Crafted as professional mechanical legs for humans, this bionic lower limb auxiliary device adopts high-precision multi-joint mechanical transmission and real-time motion sensing modules to output matched auxiliary force synchronously with human walking, climbing and heavy-load walking postures. It effectively disperses the pressure on knees, thighs and waist muscles during long-distance hiking, field work and daily mobility training, significantly alleviating persistent soreness and delaying physical fatigue. Made of lightweight high-rigidity composite materials and equipped with IP54 dustproof and waterproof sealing, these mechanical legs for humans operate stably in snowy, high-temperature and muddy wild environments. The fully adjustable binding system adapts to users of different heights and leg circumferences, paired with detachable large-capacity lithium batteries to support all-day continuous outdoor use. Suitable for outdoor explorers, field operators, the elderly and people with weak lower limbs, this set of human-specific mechanical legs realizes smooth human-machine coordination and effectively breaks through the natural physical limits of long-time walking.