In order to improve the luminous efficiency of GaN-based light-emitting diodes (Light Emitting Diode, LED), a bow tie type silver metal array with a simple process and low cost is designed, and the structure is integrated on the surface of the GaN-based light-emitting diode. Without damaging the epitaxial structure, the light extraction efficiency of light-emitting diodes in different wavelength bands can be improved by exciting the local surface plasmon effect. The finite-difference time-domain method is used to systematically simulate and calculate the influence of bow tie type silver metal arrays on the light extraction efficiency of GaN based light-emitting diodes at different incident wavelengths. The results show that the photoluminescence peak intensity of the LED with the central wavelength of 370, 425 and 525 nm is increased by 71.1%, 148.2% and 105.9%, respectively, compared with that of the LED without surface structure.