A phase shifter and an antenna, in the field of communications technologies. The phase shifter includes a cavity, and a fixed component, a sliding component, a control rod configured to control sliding of the sliding component, and a dielectric portion in the cavity. A first strip group is disposed in the fixed component, where the first strip group includes two strips. The sliding component is located above the fixed component, and a second strip group is disposed in the sliding component. The second strip group includes two strips, and the two strips of the second strip group are electrically coupled to the two strips of the first strip group respectively.