A phase shifter, comprising a cavity, a rotating shaft, a main printed circuit board, PCB, a first slidable part, and a second slidable part, wherein in the cavity, the first slidable part is located on a front side of the main PCB and is coupled to the main PCB, the second slidable part is located on a rear side of the main PCB and is coupled to the main PCB, and the rotating shaft is inserted into the cavity and is connected to the first slidable part and the second slidable part for driving the first slidable part and the second slidable part for rotating relative to the main PCB, wherein the cavity is configured to form an upper ground layer and a lower ground layer of a strip line of the phase shifter; the main PCB comprises a main signal line, a primary central coupling section, a first arc-shaped phase delay line, and a second arc-shaped phase delay line, which are formed on the front side of the main PCB, wherein the main signal line is configured to receive an input signal and is connected to the primary central coupling section, the primary central coupling section is close to the rotating shaft and is disposed on two sides of a substrate of the main PCB, circuits of the primary central coupling section are in communication with each other, the first arc-shaped phase delay line and the second arc-shaped phase delay line are distributed with a center of the rotating shaft as a center of a circle and are located on an outer side of the primary central coupling section, the first arc-shaped phase delay line has two first output ports, and the second arc-shaped phase delay line has two second output ports; the first slidable part comprises a first secondary central coupling section, a first transmission section, and a first delay line coupling section, wherein the first secondary central coupling section is close to the rotating shaft and is coupled to the primary central coupling section, and the first delay line coupling section is connected to the first secondary central coupling section by using the first transmission section, so that the first delay line coupling section is coupled to the first arc-shaped phase delay line; and the second slidable part comprises a second secondary central coupling section, a second transmission section, and a second delay line coupling section, wherein the second secondary central coupling section is close to the rotating shaft and is coupled to the primary central coupling section, and the second delay line coupling section is connected to the second secondary central coupling section by using the second transmission section, so that the second delay line coupling section is coupled to the second arc-shaped phase delay line; wherein the first slidable part is a first PCB, wherein the first secondary central coupling section, the first transmission section, and the first delay line coupling section are formed on a front side of the first PCB; and the second slidable part is a second PCB, wherein the second secondary central coupling section, the second transmission section, and the second delay line coupling section are formed on a front side of the second PCB; wherein the first arc-shaped phase delay line and the second arc-shaped phase delay line are located on one side of the rotating shaft.