The invention discloses a power source supply system for a line patrol robot. The power source supply system comprises a liquid fuel cell and storage battery hybrid power system, a control system anda line patrol robot high-altitude liquid fuel supplementing device. The power source adopted by the power source supply system for the line patrol robot is hybrid power formed by combining the liquidfuel cell and the storage battery, a liquid fuel cell serves as main power, a storage battery serves as auxiliary power, and it is guaranteed that the line patrol robot can reach a fuel supply stationto supply liquid fuel through the control system when fuel is exhausted. Moreover, the robot can supplement fuel at high altitude without being taken down from a line.