The utility model discloses an automatic charging system of robot, the system includes charging seat and the robot, the charging seat includes identification module, control module and emission module, emission module includes power, high -frequency inverter, transmit controller and transmitting coil, the robot is the robot, the robot includes electric quantity detection module, drive module, receiving module and energy storage module, receiving module includes receiving coil, rectifier and reception control unit. The utility model discloses can go to charging position at driven robot under the electric quantity condition inadequately to through on -off control signal start -up charging process, realize the supply of electric quantity in time, improved system security nature, utilize magnetic coupling resonance technology realization emission module and receiving module's energy transfer, the transmission efficiency of this technique is high, and save time provides work efficiency.