A　microwave　photonic　mixer　based　on　a　frequency-doubled　local　oscillator　(LO)　is　proposed.　The　carrier-suppressed　single-sideband　(CS-SSB)　modulation　of　the　-first-order　radio　frequency　(RF)　and　+second-order　LO　sidebands　can　be　generated　by　using　a　dual-polarization　dual-parallel　Mach-Zehnder　modulator　(DP-DPMZM),　an　electrical　90　degrees　hybrid　coupler,　and　an　optical　bandpass　filter.　The　upconverted　intermediate　frequency　(IF)　signal　with　the　frequency　of　omega(RF)　+　2　omega(LO)　is　output　by　frequency　beat　at　a　photodetector.　Meanwhile,　the　-first-order　RF　sideband　can　be　easily　changed　to　+first-order　RF　sideband　by　adjusting　one　dc　bias　voltage　of　the　DP-DPMZM.　The　downconverted　IF　signal　with　the　frequency　of　omega(RF)　-　2　omega(LO)　is　obtained　correspondingly.　The　experimental　results　show　that　the　spur　suppression　ratios　of　upconverted　and　downconverted　IF　signal　are　19.0　dB　and　25.5　dB,　respectively.　The　spurious-free　dynamic　range　of　the　proposed　mixer　is　96.5　dB.Hz(2/3).　The　output　electrical　spectrums　are　pure　owing　to　the　optimal　design　of　the　CS-SSB　modulation.　The　proposed　mixer　reduces　the　frequency　requirement　of　LO　signal　since　the　second-order　LO　single　sideband　is　used,　and　the　upconversion　and　downconversion　can　be　switched　to　each　other　by　a　simple　electrical　operation.