High-harmonic generation in metasurfaces, driven by strong laser fields, has been widely studied. Compared to plasma, all-dielectric nanoscale metasurfaces possess larger nonlinearity response and higher damage threshold. Additionally, it can strongly localize the driven field, greatly enhancing its peak amplitude. In this work, we adopt a Fano resonant micro-nano structure with transmission peaks at different wavelengths and explore its nonlinear response by both single and two-color pump fields. Compared to the high-order harmonics induced by the first resonant wavelength, the intensity of the high-harmonic radiation results is enhanced by one order of magnitude, when the metasurface is driven by various resonant and non-resonant wavelength combinations of a two-color field.