In order to strengthen the electric field between two gold nanowires, a kind of structure was designed by putting them into periodical subwavelength slits. This structure combined the effect of amplifying electric field from the near-field coupled effect and the quasi-Fabry-Perot resonance. Theoretical study indicated that the electric field between gold nanowires showed periodical variation when depth of slits changes, and the peak of electric field appeared when Quasi-Fabry-Perot resonance happened, and nanowires were able to modulate the depth of resonance. The electric field turned out a sharp peak when the period was approaching to the wavelength of incident light, and it decreased rapidly as the interval of wires increased. According to the result calculated by finite element method, enhancing effect is considerable when the interval varies from 1 nm to 2 nm. It gets a 200 electric field enhancement which means a 109 Raman enhanced factor in hot spot between the two gold nanowires in subwavelength slits by reasonably adjusting the period and depth of the slits, which is three orders of magnitude than two lonely wires.