Abstract: The disclosure discloses a method for establishing an ultra wide band (UWB) class I Chebyshev multi-section Wilkinson power divider having equal ripple isolation characteristic, including: step 1, determining a Chebyshev equal ripple order required in the designed circuit and calculating a class I Chebyshev polynomial in the same order, and meanwhile determining the equal ripple heights of S11 and S32; step 2, carrying out even-mode analysis on the power divider, calculating an ABCD matrix expression under the even-mode condition according to the Chebyshev equal ripple order and the number of the required coupled line units, calculating equivalent conditions, and then obtaining a Zev impedance value of each section of coupled line; step 3, carrying out odd-mode analysis on the power divider so that each zero position and each peak ripple position of S32 and S11 are the same.