We study supercontinuum (SC) generation in sapphire pumped by two femtosecond lasers with dual wavelengths of 800 nm and 1054 nm. In comparison with the case pumped by single-wavelength pulses, the conversion efficiencies in the visible and infrared regions are enhanced by almost an order of magnitude, and the SC spectrum can be much flatter with dual-wavelength pulses pumping. The ultrabroad SC spanning from 350 nm to 1600 nm is obtained experimentally, which covers an octave of the pumping wavelengths.