An effective method to enhance the intensities of the attosecond pulses has been proposed by using the asymmetric polarization gating (PG) technology. The results show that when the two circularly polarized pulses are asymmetry in pulse intensity, not only the modulation of the harmonics can be decreased; but also the intensities of the harmonics can be enhanced, correspnding to a 85 eV supercontinuum with the near-single quantum path contribution. Finally, by superposing the harmonics of this supercontinuum, a single attosecond pulse with the full width at half maximum of 52 can be obtained.