A two-dimensional simulation of electrical and optical characteristics of dual-wavelength LED (light-emitting diode) with doped GaN interval layer is conducted with software.It shows that by the use of doped GaN interval layer, we can solve the luminescence intensity disparity of the two kinds of quantum wells in dual-wavelength LED. And through control of the thickness of the interval layer, we can adjust the relative luminescence intensity of the two kinds of quantum wells. Therefore, the effect of spectrum-control in dual-wavelength LED is due to the blocking effect of holes or electrons by doped GaN interval layer.