The invention discloses a bionic passive rebound mechanical leg which comprises a body, a
crank connecting rod mechanism, a passive rebound mechanism and a foot end, wherein the
crank connecting rod mechanism comprises a
crank, a
thigh bone and a rocker; the passive rebound mechanism comprises a
fixed slide block, a shin bone, an upper outer spring, a
pulley, a movable slide block, a splinter bone, a lower outer spring, a stopper, a metatarsal bone, a pin shaft and an inner spring mechanism; the inner spring mechanism comprises a base, an inner shaft, a compressed spring plate, a compressed spring plate base, a baffle, a small spring, a small spring guide rod and a
brake cable; the foot end comprises a torsional spring and toes; the toes are made from flexible
storage energy materials. According to the bionic passive rebound mechanical leg, based on the dimension parameters of ostrich hind limbs and passive rebound characteristics of joints among ostrich tarsal bones, the passive rebound function of the joints among the tarsal bones of bionic ostrich hind limbs is realized by utilizing the passive rebound mechanism, so that the
energy consumption can be reduced, the ground
impact force can be absorbed at initial contact by utilizing an elastic element, and the buffering and damping effects are achieved.