The invention discloses a mobile terminal antenna system and a mobile terminal. The antenna system comprises a metal frame of the mobile terminal, an NFC feed source, a first matching circuit, a diversity antenna feed source, a second matching circuit, a zeroth inductor and reference ground; at least two slots are formed in the metal frame; a metal frame section between any adjacent slots is a first metal frame; the NFC feed source is connected with the first metal frame through the first matching circuit; the diversity antenna feed source is connected with the first metal frame through the second matching circuit; one end of the zeroth inductor is connected with the first metal frame, and the other end of the zeroth inductor is grounded; the NFC feed source, the first matching circuit, the first metal frame, the zeroth inductor and the reference ground form an NFC antenna system; the diversity antenna feed source, the second matching circuit and the first metal frame form a diversity antenna system; and the NFC antenna system and the diversity antenna system share the first metal frame as an antenna radiating body. With the mobile terminal antenna system of the invention adopted, the problems of large occupied space and high cost of a mobile terminal built-in antenna can be solved.