From a theoretical analysis, the frequency multiplication factor of 2k microwave signal with a minimum optical sideband suppression ratio of 45.48 dB and a minimum spurious suppression radio of 39.46 dB is generated by properly adjusting the direct current bias points and the modulation index of the cascaded Mach-Zehnder modulators without changing the optical filter. Moreover, the performance of sideband selection with the direct current bias point of Mach-Zehnder modulator, the amplitude and the initial phase difference of the modulation signal deviate from the ideal values is analyzed. Furthermore, the performance is evaluated by simulation experiment. The simulation results validate the feasibility and effectiveness of the proposed approach.