In the past three decades, high-order harmonic generation (HHG) has attracted much attention due to its promising applications on creating table-top coherent extreme-ultraviolet (EUV/XUV) or X-ray sources, synthesizing attosecond pulses, probing electron dynamics and making ”molecular movies”, etc. We review our recent experimental and theoretical progresses in HHG driven by two-color laser fields, including broadening of XUV supercontinuum, generation of isolated attosecond pulses (IAPs), selection of long or short quantum trajectories, enhancement of HHG yield, creation of wavelength-tunable, bandwidth-controlled XUV emission, etc.