The invention discloses a dual-polarized array antenna gain method and a structure thereof. A substrate, multiple radiation metal surfaces, multiple 1/2 wavelength conductors, a first signal feed-in network, a second signal feed-in network, a first signal feed-in point and a second signal feed-in point form a dual-polarized array antenna. When a signal is fed in via the first signal feed-in point of the first signal feed-in network, a 1/2 wavelength is added to the signal, through 1/2 wavelength conductor conversion, phases of the radiation metals are consistent but current is not consistent, or the signal is fed in via the second signal feed-in point of the second signal feed-in network, through 1/2 wavelength conductor conversion, phases of the radiation metals are consistent but current is not consistent, and thus, horizontal and vertical transmitting and receiving power strength of the antenna can be enhanced.