A　high-accuracy　and　wide-range　optical　delay　measurement　method　based　on　linear　frequency　modulation　(LFM)　of　a　microwave　source　is　proposed,　which　can　measure　the　delay　of　each　channel　in　a　parallel　multichannel　interference　structure.　The　light　wave　emitted　by　the　light　source　is　injected　into　the　dual-parallel　Mach-Zehnder　modulator　(DPMZM)　as　a　carrier　wave.　The　LFM　microwave　signal　is　loaded　into　the　radio　frequency　ports　of　the　DPMZM　through　a　90　degrees　hybrid　couple,　and　the　bias　voltages　of　the　DPMZM　are　adjusted　to　make　it　work　in　carrier　suppression　single　sideband　(CS-SSB)　modulation　mode.　The　CS-SSB　optical　signal　output　by　the　modulator　enters　the　test　links,　including　a　Mach-Zehnder　interference　loop　composed　of　the　reference　arm　and　the　device　under　test　arm.　Then,　the　output　optical　signal　of　the　interference　loop　is　input　into　a　photodetector,　and　the　intermediate　frequency　(IF)　signals　are　obtained　by　the　beat　frequency.　The　frequency　of　the　IF　signal　is　obtained　through　data　acquisition　and　fast　Fourier　transform　calculation.　Thus,　the　delay　time　is　calculated.　By　increasing　or　decreasing　the　LFM　signal　scanning　time,　the　delay　measurement　range　can　be　extended,　or　the　measurement　accuracy　over　a　short　distance　can　be　improved.　The　feasibility　of　this　method　is　verified　by　experiments,　and　the　delay　of　parallel　multichannel　measurement　is　carried　out.