Compared　with　traditional　electrical　methods,　radio　frequency　self-interference　cancellation　(SIC)　based　on　microwave　photonic　technology　has　the　advantages　of　large　bandwidth,　high　precision,　low　loss　and　anti-electromagnetic　interference.　For　distributed　full-duplex　communication　system,　a　SIC　method　based　on　cascade　modulation　is　studied.　The　cancellation　depth　of　the　system　for　single-frequency　signals　is　more　than　43　dB,　and　the　cancellation　depth　for　wideband　signals　is　more　than　22　dB,　and　the　recovered　useful　signals　is　obtained.　The　system　adopts　cascade　modulation,　and　the　isolation　degree　of　LO　and　RF　signal　is　high.　In　this　scheme,　the　signal　after　SIC　can　be　transmitted　to　the　central　office　through　a　long　fiber.　The　proposed　approach　supplies　an　architecture　for　distributed　systems　with　both　down-conversion　and　SIC.　©　2022　SPIE.