Abstract: A design method for a double-layer dual-mode microstrip equalizer is proposed in this paper. The resonant frequency and Q value are analyzed using the odd and even mode analysis method as a function of parameters of the equalizer, and the software simulation results are consistent with the theoretical analysis. The new dual-mode equalizer proposed in this article consists of a dual-mode resonant unit, a coupling hole, and a transmission line. The resonant unit is composed of a transverse arm and a longitudinal arm loaded with resistors. The operating frequency of the resonant unit can be adjusted by the length of the transverse and longitudinal arms, and the Q value can be adjusted by the resistance value loaded on the resonant unit. The two resonant modes can be independently adjusted, making it flexible and convenient to use. This is a new idea for the design of microstrip equalizers. At the end of this article, the designed equalizer was processed and tested, and the test results verified the correctness of the design.