Multi-frequency antenna and terminal device

Provided are a multi-frequency antenna and a terminal device. The multi-frequency antenna comprises a feed portion connected to a capacitor assembly to form a feed circuit, a feed matching circuit electrically connected between a feed radio-frequency circuit and the feed circuit; and a radiation portion electrically connected to the feed circuit and a grounding portion respectively, the grounding portion being electrically connected to the horizontal plane, wherein a first resonance loop is formed from the feed circuit to an end of the radiation portion away from the grounding portion, the first resonance loop generating a first resonance frequency and a second resonance frequency.