This application provides a terminal antenna, including a first radiator, a second radiator, a third radiator, a first tuning circuit, and a second tuning circuit. The third radiator includes a low frequency radiator and a medium-high frequency radiator. The first tuning circuit is configured to adjust a frequency of a resonance of a ¾λ mode of a medium-high frequency produced by the low frequency radiator to be less than a frequency of a resonance of a left-handed antenna mode. The second tuning circuit is configured to adjust the frequency of the resonance of the left-handed antenna mode to be greater than the frequency of the resonance of the ¾λ mode of the medium-high frequency produced by resonating by the low frequency radiator. Values of both the first distance and the second distance are less than 1/16λ of a frequency band in which the third radiator produces a low frequency.