A phase shifter, an antenna, and a base station are provided. The phase shifter in the present invention includes a feed unit, a tapping element, a conductor section, and a ground element, and the feed unit is electrically connected to the tapping element. The tapping element is electrically connected to the ground element when being shifted by a preset angle by using a port of the conductor section as a start position, so that a transmit signal is reflected to an input port of the feed unit, and whether a cable is correctly connected is determined according to the signal of the input port, thereby signal transmission accuracy of an antenna is ensured.