An approach to generate a microwave signal with multiplication frequency is studied and verified theoretically and experimentally. Based on big signal phase modulation and the dispersion of a single-mode fiber, the high order of microwave harmonic signal is generated. A tunable single passband microwave photonic filter is used to select a specific harmonic signal by tuning the sliced space of broadband optical source. Based on the theoretic analysis, an experimental system is established, and the harmonic signals at 10 GHz and 15 GHz are produced by applying a low-frequency signal at 5 GHz. It can be seen the 10 dB bandwidth of the signal is a few tens hertz, and the power fluctuation is 1 dB～2 dB.