Electromagnetic　composite　rheological　polishing　(EMRP)　is　a　new　ultra-precision　machining　technology　that　combines　electro-rheological　polishing　(ERP)　and　magneto-rheological　polishing　(MRP).　The　key　technology　of　the　polishing　method　is　the　preparation　of　electromagnetic　composite　rheological　fluid　(EMRF)　with　both　ERP　and　MRP,　especially　the　preparation　of　composite　particles　with　electro-　and　magneto-rheological　effects.　In　this　study,　the　EMRF　was　prepared　by　using　electromagnetic　two-phase　particles　with　abrasive　characteristics.　The　electromagnetic　two-phase　composite　particles　are　synthesized　in　two　steps:　the　coupling　method　and　sol-gel　method.　The　two-step　method　successfully　prepared　the　electromagnetic　two-phase　composite　particles　with　nano-diamond　particles　embedded　randomly　on　the　surface.　The　electro-rheological　shear　stress　of　EMRF　can　reach　160.7　Pa　when　the　test　parameter　voltage　is　2.5　kV,　and　magneto-rheological　shear　stress　of　EMRF　can　reach　4076　Pa　when　the　electromagnet　excitation　current　is　3　A.　When　a　fused　silica　glass　is　polished　under　a　single　magnetic　field,　the　material　removal　depth　reaches　a　maximum　of　2.7　μm　at　a　radius　of　13.5　mm.　Under　the　action　of　the　electromagnetic　compound　field,　the　removal　profile　of　the　work-piece　is　smoother,　and　the　material　removal　depth　reaches　the　maximum　value　of　2.1　μm　at　a　radius　of　10.5　mm.　This　proves　that　the　stiffness　distribution　of　the　polishing　pad　under　the　electromagnetic　composite　field　is　more　dispersed　than　that　under　a　single　field.　Therefore,　the　distribution　of　electromagnetic　two-phase　composite　particles　can　be　controlled　by　applying　an　electromagnetic　composite　field,　which　provides　a　good　foundation　for　the　abrasive　control　technology　of　EMRP.　©　2022　IOP　Publishing　Ltd.