A　microwave　photonic　single　sideband　mixer　based　on　a　dual-polarization　dual-parallel　Mach-Zehnder　modulator　(DP-DPMZM)　modulator　is　proposed.　A　radio　frequency　(RF)　signal　and　a　local　oscillator　(LO)　signal　were　loaded　to　the　modulator　through　two　electrical　90　degrees　hybrid　couplers,　respectively.　The　carrier-suppressed　single　sideband　(CS-SSB)　modulation　was　achieved　by　setting　the　six　DC　biases　of　the　DP-DPMZM　modulator.　Experimental　results　demonstrate　that　the　proposed　mixer　for　both　the　upconversion　and　downconversion　has　high　purity　with　a　large　suppression　ratio　of　the　undesired　signals　(similar　to　30　dB).　Since　the　RF　and　LO　signals　respectively　drive　the　DP-DPMZM　modulator　through　two　electrical　90　degrees　hybrid　couplers,　the　proposed　link　has　good　RF/LO　isolation　that　reaches　49.1　dB.　The　proposed　microwave　photonic　mixer　provides　an　alternative　with　high　purity　and　isolation　for　the　transmitter,　receiver　and　phased　array　beamforming　in　microwave　photonic　applications.