A metal frame antenna and a terminal device are provided. The metal frame antenna includes N metal radiating elements between N+1 gaps, an end part of a metal radiating element on at least one of two sides of each of N−1 gaps between the N metal radiating elements is connected to a grounding part, the N metal radiating elements and respectively connected feeding branch circuits and grounding pails form N antennas, and N is an integer not less than 3.