A motor cooling structure, comprising: a plurality of branch flow-channels configured to be circumferentially arranged on a stator of a motor around an axis of the motor and run through the stator of the motor; a plurality of shell flow-channels, which are configured to be arranged on a side wall of a reducer shell, comprising: a liquid inlet flow-channel, shell long flow-channels, and a liquid outlet flow-channel, wherein the liquid inlet flow-channel, the shell long flow-channels, and the liquid outlet flow-channel are configured to be circumferentially arranged on the reducer shell around the axis of the motor; end cover flow-channels, comprising end-cover long flow-channels, and a plurality of the end-cover long flow-channels configured to be circumferentially arranged on a motor end cover around the axis of the motor; wherein the shell flow-channels, the plurality of branch flow-channels and the end cover flow-channels form a continuous total flow-channel; a liquid inlet configured to be disposed on the reducer shell and being in communication with the liquid inlet flow-channel; and a liquid outlet configured to be disposed on the reducer shell and being in communication with the liquid outlet flow-channel, wherein a first resin glue is configured to be disposed outside one end of coils of the motor close to the reducer shell, and wherein the first resin glue is located inside a circumference formed by the shell flow-channels and configured to form a closed space with the reducer shell as a cooling flow-channel for the first resin glue, wherein an inner wall of the liquid outlet flow-channel is defined with an opening, and the opening of the liquid outlet flow-channel and the liquid outlet are respectively arranged on both sides of the first resin glue. a plurality of branch flow-channels configured to be circumferentially arranged on a stator of a motor around an axis of the motor and run through the stator of the motor; a plurality of shell flow-channels, which are configured to be arranged on a side wall of a reducer shell, comprising: a liquid inlet flow-channel, shell long flow-channels, and a liquid outlet flow-channel, wherein the liquid inlet flow-channel, the shell long flow-channels, and the liquid outlet flow-channel are configured to be circumferentially arranged on the reducer shell around the axis of the motor; end cover flow-channels, comprising end-cover long flow-channels, and a plurality of the end-cover long flow-channels configured to be circumferentially arranged on a motor end cover around the axis of the motor; wherein the shell flow-channels, the plurality of branch flow-channels and the end cover flow-channels form a continuous total flow-channel; a liquid inlet configured to be disposed on the reducer shell and being in communication with the liquid inlet flow-channel; and a liquid outlet configured to be disposed on the reducer shell and being in communication with the liquid outlet flow-channel, wherein a first resin glue is configured to be disposed outside one end of coils of the motor close to the reducer shell, and wherein the first resin glue is located inside a circumference formed by the shell flow-channels and configured to form a closed space with the reducer shell as a cooling flow-channel for the first resin glue,