A phase shifter, comprising: a first circuit layer, the first circuit layer including an input branch and a first output branch; a second circuit layer, the second circuit layer being movable relative to the first circuit layer, and, in case that the second circuit layer moves to a first position relative to the first circuit layer, the first output branch being disconnected from the input branch, in case that the second circuit layer moves to a second position relative to the first circuit layer, the first output branch being connected to the input branch; and a dielectric plate, configured to move relative to the first circuit layer and to drive the second circuit layer to switch between the first position and the second position, characterized in that the movement of the dielectric plate relative to the first circuit layer includes a forward movement and a reverse movement in a longitudinal direction; the switching of the second circuit layer from the first position to the second position is realized by the reverse movement of the dielectric plate, and the switching of the second circuit layer from the second position to the first position is realized by the forward movement of the dielectric plate; and the dielectric plate is provided with a first driving portion for driving the second circuit layer to move from the second position to the first position, a second driving portion for driving the second circuit layer to move from the first position to the second position; and the first driving portion and the second driving portion are spaced apart, wherein the driving portions drive the second circuit layer in a certain angle direction relative to the moving direction of the dielectric plate. a first circuit layer, the first circuit layer including an input branch and a first output branch; a second circuit layer, the second circuit layer being movable relative to the first circuit layer, and, in case that the second circuit layer moves to a first position relative to the first circuit layer, the first output branch being disconnected from the input branch, in case that the second circuit layer moves to a second position relative to the first circuit layer, the first output branch being connected to the input branch; and a dielectric plate, configured to move relative to the first circuit layer and to drive the second circuit layer to switch between the first position and the second position, characterized in that the movement of the dielectric plate relative to the first circuit layer includes a forward movement and a reverse movement in a longitudinal direction; the switching of the second circuit layer from the first position to the second position is realized by the reverse movement of the dielectric plate, and the switching of the second circuit layer from the second position to the first position is realized by the forward movement of the dielectric plate; and the dielectric plate is provided with a first driving portion for driving the second circuit layer to move from the second position to the first position, a second driving portion for driving the second circuit layer to move from the first position to the second position; and the first driving portion and the second driving portion are spaced apart, wherein the driving portions drive the second circuit layer in a certain angle direction relative to the moving direction of the dielectric plate.