Abstract: A power-assisted negative pressure type flexible exoskeleton system used for an extravehicular spacesuit. The system includes an exoskeleton pneumatic control system, a plurality of inertial sensors, a plurality of negative pressure type flexible actuators and a plurality of flexible bending sensors, wherein pneumatic energy is provided for the exoskeleton system by a gas source in the exoskeleton control system, compressed air is cleaned by a water-separating gas filter, normal work of a pneumatic actuating element is guaranteed, a pressure reducing valve and a pressure gauge carry out voltage stability control on the output pressure of the gas source, a two-position two-way valve serves as a gas source switch valve, and three-position three-way valves, proportional pressure valves and the flexible actuators form four pneumatic control loops of the left and right elbow joints and the left and right knee joints of the exoskeleton system.