Disclosed herein is a processing method for playing motion-including multimedia content using a network-based robot system. The method including the step at which the service server forms and stores motion-including multimedia content data packets by inserting synchronized robot terminal motion control data into a multimedia content file divided at packet playing time intervals; the step at which, when a user issues a command to play specific motion-including multimedia content in a specific robot terminal, the command is transmitted to a service server; the step at which, in response to the transmitted command, the service server reads motion-including multimedia content data packets corresponding to the specific motion-including multimedia content and sequentially transmits the read motion-including multimedia content data packets to the buffer of the specific robot terminal; and the step at which the specific robot terminal sequentially stores the motion-including multimedia content data packets in the buffer, and sequentially reads and plays the motion-including multimedia content data packets at the packet playing time intervals.