A terminal antenna, comprising a first radiator, a second radiator, a third radiator, a first tuning circuit, and a second tuning circuit, wherein the third radiator, the first radiator, and the second radiator are terminal frame antenna radiators and spaced by slots, and the first radiator, the second radiator, and the third radiator are respectively connected to a first feed, a second feed, and a third feed for signal transmission; the third radiator comprises a low frequency radiator constituting a low frequency antenna and a medium-high frequency radiator constituting a medium-high frequency antenna, and the low frequency radiator and the medium-high frequency radiator are spaced by a first slot; and the low frequency radiator and the medium-high frequency radiator are self-grounded; the first tuning circuit connects the third feed and connects one side of the low frequency radiator adjacent to the first slot, and the second tuning circuit connects the third feed and an end portion of the medium-high frequency radiator located in the first slot; the low frequency radiator is configured to resonate to produce a resonance of a 1/4λ mode of a low frequency and a resonance of a 3/4λ mode of a medium-high frequency, and the medium-high frequency radiator is configured to resonate to produce a resonance of a left-handed antenna mode; and a linear distance from one end of the first tuning circuit connected to the third feed to the other end of the first tuning circuit connected to the low frequency radiator is a first distance, a linear distance from one end of the second tuning circuit connected to the third feed to the other end of the second tuning circuit connected to the medium-high frequency radiator is a second distance, and 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; and the low frequency radiator of the third radiator, the first radiator, and the second radiator jointly form a dual low-frequency antenna pattern of a 5G non-standalone, NSA, wherein the low frequency radiator and the medium-high frequency radiator are configured to work simultaneously, the first tuning circuit is configured to adjust a frequency of the resonance of the 3/4λ mode of the medium-high frequency produced by the low frequency radiator to be less than a frequency of the resonance of the left-handed antenna mode, and 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 3/4λ mode of the medium-high frequency produced by resonating by the low frequency radiator. the third radiator comprises a low frequency radiator constituting a low frequency antenna and a medium-high frequency radiator constituting a medium-high frequency antenna, and the low frequency radiator and the medium-high frequency radiator are spaced by a first slot; and the low frequency radiator and the medium-high frequency radiator are self-grounded; the first tuning circuit connects the third feed and connects one side of the low frequency radiator adjacent to the first slot, and the second tuning circuit connects the third feed and an end portion of the medium-high frequency radiator located in the first slot; the low frequency radiator is configured to resonate to produce a resonance of a 1/4λ mode of a low frequency and a resonance of a 3/4λ mode of a medium-high frequency, and the medium-high frequency radiator is configured to resonate to produce a resonance of a left-handed antenna mode; and a linear distance from one end of the first tuning circuit connected to the third feed to the other end of the first tuning circuit connected to the low frequency radiator is a first distance, a linear distance from one end of the second tuning circuit connected to the third feed to the other end of the second tuning circuit connected to the medium-high frequency radiator is a second distance, and 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; and the low frequency radiator of the third radiator, the first radiator, and the second radiator jointly form a dual low-frequency antenna pattern of a 5G non-standalone, NSA, wherein the low frequency radiator and the medium-high frequency radiator are configured to work simultaneously, the first tuning circuit is configured to adjust a frequency of the resonance of the 3/4λ mode of the medium-high frequency produced by the low frequency radiator to be less than a frequency of the resonance of the left-handed antenna mode, and 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 3/4λ mode of the medium-high frequency produced by resonating by the low frequency radiator.