With　the　rapid　development　of　the　microwave　photonic　communication　technology,　the　frequency　of　the　microwave　signal　is　expanded　to　the　Ka　waveband,　since　most　of　low　frequency　bands　are　occupied.　However,　the　current　commercial　detectors　and　signal　processing　modules　are　limited　by　bandwidth.　Therefore,　the　traditional　method　of　directly　detecting　the　microwave　signals　cannot　meet　the　actual　demands.　It　is　essential　to　achieve　the　microwave　photonic　down-conversion　from　the　high　frequency　microwave　signal　(similar　to　10　GHz)　to　the　lower　frequency　signal　(similar　to　100　MHz).　Meanwhile,　the　down-conversion　low　frequency　signal　can　be　processed　by　the　existing　mature　technology　and　low　cost　devices.　The　microwave　down-conversion　link　can　effectively　avoid　leaking　the　local　oscillator,　and　it　possesses　many　advantages　such　as　high　bandwidth　and　spurious　free　dynamic　range,　low　loss　and　low　noise.　In　this　paper,　a　microwave　photonic　down-conversion　system　is　presented　based　on　the　integrated　dual-parallel　Mach-Zehnder　modulator　(DPMZM)　to　increase　the　spurious-free　dynamic　range　as　well　as　conversion　efficient　of　microwave　photonic　link.　The　integrated　DPMZM　is　mainly　comprised　of　two　intensity　modulators　(MZM-a　and　MZM-b),　and　a　phase　shifter.　The　radio　frequency　(RF)　signal　is　loaded　into　DPMZM　to　modulate　the　optical　signal.　The　local　oscillator　is　loaded　into　the　MZM-a　to　produce　the　1st　local　oscillator　sideband,　and　two　RF　signals　are　fed　to　the　MZM-b　to　form　the　1st　RF　signal　sideband.　The　direct　current　bias　of　the　DPMZM　is　adjusted　to　output　a　high　carrier　suppressed　double　sideband　(DSB)　signal.　The　erbium-doped　fiber　amplifier　is　used　to　increase　the　power　of　light　to　match　the　power　range　of　the　detector.　The　RF　signal　sideband　and　local　oscillator　sideband　are　mixed　to　produce　the　beat　frequency,　and　the　frequency　down-conversion　can　be　achieved.　The　principle　of　frequency　down-conversion　is　elaborated　by　theoretical　analysis.　The　conversion　efficiency　and　spurious　free　dynamic　range　are　analyzed　and　simulated.　On　this　basis,　the　microwave　photonic　link　of　frequency　down-conversion　is　built.　The　performance　of　the　system　is　tested.　The　ratio　of　optical　carrier　power　to　sideband　power　of　the　DSB　signal　is　26　dB.　The　experimental　result　shows　that　the　conversion　efficiency　is　7.43　dB　and　spurious-free　dynamic　range　is　110.85　dB/Hz(2/3).　The　down-conversion　method　based　on　the　DPMZM　can　optimize　the　output　spectrum　of　the　sideband.　The　structure　of　system　is　simple　and　easy　to　implement,　so　it　is　a　good　option　for　improving　the　conversion　efficiency　and　spurious-free　dynamic　range.