The invention relates to the technical field of lower extremity exoskeletons and discloses a whole lower extremity exoskeleton and an operation method of the whole lower extremity exoskeleton. The whole lower extremity exoskeleton comprises a skeleton system, wherein the skeleton system comprises a waist-hip frame (1), a left leg frame and a right left frame, wherein each of the left leg frame and the right left frame comprises a thigh part (2), a shank part (3) and a foot part (11); an auxiliary internal and external leg expansion device (4), an auxiliary internal and external leg rotating device (5) and an auxiliary leg flexion-extension device (6) are arranged between the waist-hip frame (1) and each thigh part (2); each auxiliary internal and external leg rotating device (5) comprises a first rotating shaft (51); and the direction of each first rotating shaft (51) is vertical to the horizontal plane. The whole lower extremity exoskeleton has the function of strengthening or partially replacing the lower limb movement capacity of a user, and is suitable for users with amputated lower limbs or poor lower limb movement capacity.