The invention discloses a rotating device of a mobile satellite antenna. The rotating device comprises an antenna rack, a base, a motor, a driving belt pulley and a driven belt pulley, the base is fixedly connected with a mobile carrier, the antenna rack is rotatably connected with the base, the driving belt pulley is coaxially and fixedly connected with a driving shaft of the motor, the driven belt pulley is coaxially arranged with the central axis of the antenna rack and fixed to the antenna rack, the device is characterized in that a planetary gear train angle limiting mechanism is arrangedon the antenna rack, a winding column is fixedly arranged in the center of the base, a spiral cable sleeves the winding column, a winding fixing seat is fixedly arranged on the antenna rack, one endof the spiral cable is fixed to the winding fixing seat, and the other end of the spiral cable is fixed to the top of the winding column. The rotating device has the advantages that the limiting device is prevented from being triggered possibly when the mobile carrier turns around quickly and reverses by 180 degrees, the phenomenon of satellite loss is avoided, and in addition, a coil of the spiral cable can shrink and diffuse freely in the rotating process of the antenna rack, so that the cable is prevented from being twisted off.