A　Carrier　Suppressed　Single　Sideband(CS-SSB)　modulation　decoupling　control　technique　based　on　Dual　Parallel　Mach-Zehnder　Modulator　(DPMZM)　is　proposed　to　solve　the　problem　that　the　bias　point　of　the　DPMZM　leads　to　the　degradation　of　the　modulation　signal　under　the　influence　of　ambient　temperature,　fiber　coupling　loss　or　other　factors.　This　technique　introduces　three　non-disturbing　dithering　voltages　at　the　bias　end　of　the　modulator　and　detects　the　power　ratio　of　the　optical　signal　at　the　output　end　to　realize　CS-SSB　modulation.　Experimental　results　show　that　the　proposed　technique　can　effectively　stabilize　Optical　Sideband　Suppression　Ratio(OSSR)　above　24dB.　This　letter　also　proves　that　this　technique　is　feasible　for　other　modulators　and　has　great　practical　value　in　the　microwave　photonic　system.