The invention discloses a measuring method for ellipsometry of an attosecond pulse using a photoelectron spectrum. The method comprises the steps of: first, focusing a combined beam of a near-infraredlaser pulse and an attosecond pulse on a gaseous medium, forming a photoelectron signal containing attosecond pulse information by ionization, and collecting the photoelectron signal to obtain a photoelectron spectrum; then, calculating the relationship between the photoelectron spectrum and the attosecond pulse using the time-dependent Schr dinger equation, and obtaining the ellipsometry of theattosecond pulse by analyzing the photoelectron spectrum. The invention provides a method for obtaining the ellipsometry of the attosecond pulse by detecting the photoelectron spectrum, which is a simple and effective method with a wide range of applicability.