The utility model discloses a cross arm height -adjustable's tower pole, including the body of rod, base and cross arm, the bottom of the body of rod be provided with the base, the bottom of the bodyof rod be provided with motor installation inner chamber, the body of rod be provided with the hoist cable passageway along the axial, hoist cable passageway and motor installation inner chamber communicate with each other, motor installation in the intracavity install the motor, the motor shaft of motor on a fixed mounting reel, the top of the body of rod be provided with the pulley, the cross arm setting in the periphery of the body of rod, the cross arm pass through the hoist cable and be connected with the motor. The utility model relates to a cross arm height -adjustable's tower pole, itis rational in infrastructure, adopt to set up the motor in the inside of the body of rod, with the back of connecting of the power cord on the motor, the hoist and mount of cross arm just can be realized through the hoist cable to the motor, and are provided with the multiunit screw hole on the body of rod, the height control of convenient follow -up cross arm, and the cross arm still can carry out the tensioning to the cross arm through the hoist cable after fixed, plays the effect of enhancement.