Abstract: Reggia-Spencer is the first ferrite phase shifter used in phased-array radar, belongs to the rectangle wave-guide inter-shift phase shifter and has a cumbersome framework early. In this paper, the titanium alloy with light quality, high strength and corrosion resistance is selected as waveguide structure material. Compared with the waveguide structure of aluminum alloy and titanium alloy composed, the titanium alloy thin-walled waveguide structure is more to meet the small lightweight design requirements of airborne phase shifter and is the optimum structure design method of this kind phase shifter at present.