Multi-frequency antenna and terminal device

A multi-frequency antenna and terminal device. The multi-frequency antenna comprises a feed point (41), a matching network (42), a capacitor assembly (43), an electromagnetic radiation portion (44) and a grounding portion (45) sequentially connected to each other. The matching network (42) at least comprises a serial-connected inductor (51) and grounding capacitors (52-53) or an inductor (54). The grounding portion (45) is electrically connected to a ground surface. A first resonance loop is formed between the feed point (41) and the grounding portion (45), and generates a first resonance frequency and a second resonance frequency. The first resonance frequency operates in a CRLH mode, and the second resonance frequency operates in a half-wavelength loop mode.