The invention discloses an antenna apparatus and a mobile terminal. The antenna apparatus comprises a primary antenna assembly and a secondary antenna assembly, wherein the primary antenna assembly and the secondary antenna assembly are not connected and independently work each other; the primary antenna assembly comprises a primary radiation body and a primary feed power supply which are electrically connected with each other; the primary feed power supply feeds an electric signal into the primary radiation body; the secondary antenna assembly comprises switches, at least two secondary radiation bodies and at least two secondary feed power supplies; the at least two secondary feed power supplies are both electrically connected with the at least two secondary radiation bodies; and the switches are located between the at least two secondary radiation bodies and the at least two secondary feed power supplies, and are used for controlling connection states between the at least two secondary feed power supplies and the at least two secondary radiation bodies. The secondary radiation bodies of the secondary antenna assembly are mounted in different positions of the mobile terminal; and the secondary radiation bodies which receive and transmit WI-FI signals or radio-frequency signals are switched to the secondary radiation bodies relatively far away from the primary radiation body through the switches.