In　this　study,　the　degradation　of　Rhodamine　B　dye　based　on　the　combination　of　hydrodynamic　cavitation　(HC)　and　other　advanced　oxidation　(such　as　H2O2　and　Plasma),　which　can　improve　the　overall　degradation　efficiency　effectively.　According　to　different　operating　parameters,　such　as　inlet　pressure,　concentration　and　pH　value　of　the　solution,　the　structure　parameters　of　HC　and　system　parameters　of　plasma　device　were　optimized　to　obtain　the　maximum　degradation　of　Rhodamine　B.　And　then,　the　degradation　effects　of　combination　methods　of　HC,　Plasma,　HC　+　Plasma,　and　HC　+　H2O2　were　investigated　experimentally.　It　was　found　that　Hydrodynamic　cavitation　and　other　methods　can　cause　synergistic　effect　and　obtain　a　higher　degradation　rate.　The　maximum　degradation　rate　and　synergy　indexes　are　96.86　%　and　2.74,　respectively,　when　the　hydrodynamic　cavitation　was　combined　with　plasma　oxidation.　Comprehensively　considering　the　degradation　rate,　synergy　index　and　treatment　cost,　the　combined　effect　of　hydrodynamic　cavitation　and　plasma　oxidation　has　higher　degradation　efficiency　and　lower　operation　cost　compared　with　other　combination　modes,　which　is　more　likely　to　develop　in　the　direction　of　large-scale　application.