A dual-mode antenna device (20) includes a wireless module (207) and a second wireless module (208) transceiving signals of a first wireless network signal and a second wireless network. A first antenna (201) and a second antenna (202) transceive the signals, respectively. A first switch (203) is connected to the first antenna and a second switch (204) is connected to the second antenna. A third switch (205) is connected to the first switch, the second switch and the first wireless network module. A fourth switch (206) is connected to the first switch, the third switch and the second wireless network module. The first, third, and fourth switches collaboratively select the first antenna to transmit the wireless network signals. The second, third, and fourth switches collaboratively select the second antenna to transmit the wireless network signals.