A rotary casing of a satellite antenna having an angle adjustable display screen includes a supporting arm, a hollow casing, a rotating means and an adjusting and controlling assembly. The casing has a panel provided with two keys and a top surface provided with a window. The rotating means is provided in the casing and controlled by the keys to drive the rotation of the supporting arm. The adjusting and controlling assembly is provided in the casing and includes a control unit and a display unit. The two keys are electrically connected to the control unit to drive the supporting arm. By this arrangement, the control unit receives an adjustment instruction inputted by the keys and transmits the instruction to the rotating means to generate a corresponding amount of rotation, while the control unit converts the instruction into a numerical value to be displayed on the display unit.