Carrying a load can affect human locomotion and increase the risk of musculoskeletal injuries. In this paper, we proposed a method inspired by the running posture of ungulate species to reduce metabolic energy by controlling load motion. We developed an energy-saving exoskeleton with an active load CoM adjustment system, which enables accurate control of load CoM acceleration using active disturbance rejection control (ADRC) technology. Finally, we tested the energy-saving exoskeleton system, and the results showed an <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$8.82 \pm 4.19\%$</tex-math></inline-formula> decrease in the integrated EMG signals of rectus femoris, as well as an <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$8.21 \pm 3.85\%$</tex-math></inline-formula> reduction in net metabolic rate. These findings validate the effectiveness of our energy-saving exoskeleton.