The effect of the two-color laser wavelength on intense terahertz generation was studied based on the transient photocurrent model. Theoretical calculation proves that the terahertz signal will increase with the increase of laser wavelength, and this trend will not vary with the variation of the pulse intensity, the pulse duration, the laser phase and the intensity ratio of the two-color laser. The distribution of terahertz spectrum will not change with the variation of the laser wavelength. Furthermore, the influence of laser wavelength on terahertz generation is analyzed, and the physical mechanism of this effect is explained by the free electron density and the drift current density.