The invention discloses a UWB (ultra wide band) two-phase shifter. The two-phase shifter comprises an active balun, a first differential amplifier, a second differential amplifier, a third differential amplifier, a switch matrix, an RC orthogonal network and a single-pole double-throw switch, wherein the active balun receives a single-ended signal, and converts the single-ended signal into double-ended signals which are connected to two input ends of the first differential amplifier respectively; the first differential amplifier performs waveform shaping and gain compensation on the received two paths of signals, and selects different branches through a switch matrix to realize 180-degree phase shift; the double-end signal passes through the switch matrix and generates an orthogonal signalthrough a cascaded RC orthogonal network, and the rear stage of the RC orthogonal network is cascaded with the second differential amplifier and the third differential amplifier respectively; the single-pole double-throw switch selects different branches of the second differential amplifier and the third differential amplifier to generate 90-degree phase shift stepping quantity, so 90-degree phase shift quantity, 180-degree phase shift quantity and 270-degree phase shift quantity are realized. The phase shifter has the advantages of ultra-wide band, high phase shifting precision, good amplitude balance, simple control mode and high integration level.