The invention discloses a method and a device for generating and adjusting a circular polarization or elliptic polarization higher harmonic. The method is characterized in that: two beams of linear polarized lights with different frequencies are utilized to drive a gas medium to radiate a higher harmonic, and the efficiency of radiating the higher harmonic is ensured through adjustment of a relative phase of a bicolor field; a polarization included angle and an intensity ratio of the bicolor field are adjusted, and the ellipsometry of the radiated higher harmonic is adjusted, so that the intensities of the radiated odd and even higher harmonics are obviously different under the proper polarization included angle and intensity ratio, and the odd and even higher harmonics have the same rotation property respectively and can be used for synthesizing high-efficiency circular polarization or elliptic polarization attosecond pulses. The method of the invention is a practical method for generating and adjusting a coherent extreme ultraviolet ellipsometry.