The charging system comprises an outdoor track mobile robot charging system and method. The system comprises a track on which a robot runs, a power supply device and a charging device, the power supply device comprises an alternating current power supply module and a solar power supply module, the charging device comprises a charging upper fork part and a charging lower fork part which are arranged on the robot, and the charging lower fork part is arranged along the track. The solar power supply module and the alternating current power supply module are arranged, when the solar energy is not enough, the outdoor track mobile robot charging system can be automatically converted into alternating current charging; the two types of supply sources can be automatically switched without influenceof work of the robot; the solar energy is taken as the energy of the robot with energy conservation and environmental protection; and moreover, a plurality of solar panels are arranged on the track toobtain sufficient electric quantity through conversion, and the load of the robot is reduced so that the work efficiency of the robot is improved and the service life of the robot is prolonged.