The invention relates to the technical field of sound boxes, and provides a sound box and an inverter tube thereof. The sound box comprises the inverter tube, wherein the inverter tube comprises a hollow tube body, and two ends of the tube body are separately an inner end part and an outer end part. The outer end part is horn-shaped; and both of the inner end part and the outer end part are provided with ports. A cross section with a part of tube wall inclining toward the tube body is at least arranged on the port of the inner end part. According to the sound box provided by the invention, the area of the port of the inner end part is increased, so that pressure difference changes and air flow velocity changes are well buffered in a process when the airflow inflows and outflows from the inverter tube, and thus the wind noise is reduced. Compared with the inverter tube with the two horn-shaped end parts, the inverter tube provided by the invention requires no single modeling according to the box body of each size, and the tube body can be cut after the necessary length of the tube body and the outline shapes of the ports of the inner end parts are determined according to the size of the specific box body. Therefore, the inverter tube provided by the invention reduces the production cost while reducing the wind noise, and has very good universality.