In order to enhance conversion efficiency and spurious free dynamic range of microwave photonic link, we present a microwave photonic down-conversion system based on an integrated dual-parallel Mach Zehnder modulator (DPMZM) and microwave photonic filter. The principle of frequency down conversion is analyzed. We demonstrate the conversion efficiency of system through theoretical derivation and simulation. The performance of the microwave photonic link is tested experimentally. It is found that the spurious free dynamic range of the proposed method is up to 102.5dB/Hz2/3 and the conversion efficiency is up to -22.01dB. The integrated dual-parallel Mach-Zehnder modulator link can serve as a good alternative to improve the conversion efficiency and spurious free dynamic range.