A　dual-channel　phase-tunable　down　converter　with　local　oscillator　(LO)　frequency　doubling　is　proposed　by　using　a　commercial　dual-polarization　dual-drive　Mach-Zehnder　modulator　(DP-DMZM)　and　a　specially　designed　dual-channel　phase　modulator　(DP-PM).　A　radio　frequency　(RF)　signal　is　injected　to　one　of　sub-DMZMs　in　the　DP-DMZM,　and　a　LO　signal　modulates　another　sub-DPMZM.　An　optical　bandpass　filter　(OBPF)　is　used　to　filter　out　the　unwanted　sidebands,　and　only　the　+2nd-order　LO　and　+1st-order　RF　sidebands　are　remained　and　output　to　the　DP-PM.　The　DP-PM　is　composed　by　two　parallel　PMs　with　different　modulation　efficiency　between　orthogonal　polarizations.　Each　bias　voltage　of　the　DP-PM　can　linearly　vary　the　phase　shift　between　the　RF　and　LO　modulated　optical　sidebands.　After　detected　by　a　photodetector,　the　down　converted　signal　with　doubled　LO　frequency　and　dual-channel　phase　shift　can　be　obtained.　The　principle　of　the　proposed　link　is　verified　and　the　experiments　are　carried　out.　The　experimental　results　show　that　the　average　spur　suppression　ratio　of　the　down-converted　signals　is　29.15　dB.　The　spurious-free　dynamic　range　(SFDR)　of　the　down　converter　is　103.94　dB.Hz(2/3)　.　The　continuous　and　dependent　dual-channel　phase　shift　with　the　full　range　of　360　degrees　can　be　experimentally　achieved.　The　proposed　down　converter　integrates　multiple　function　in　a　link,　and　has　the　merit　of　high　electrical　purity　and　convenient　operation.