Electrical　capacitance　tomography　(ECT)　is　a　non-invasive　multiphase　flow　detecting　technique.　Sensor　optimal　design,　which　is　multi-parametric　with　multiple　indicators,　is　one　of　the　key　parts　of　the　ECT　technique.　In　this　paper,　an　enhanced　objective　function-combination　fuzzy　index　of　the　ECT　(CFIECT)　is　defined　and　presented　as　a　multi-parametric　indicator　for　the　optimization　of　the　sensor　for　paraffin　deposition　detection.　In　order　to　evaluate　the　effectiveness　of　the　CFIECT　and　optimize　the　sensor　structure,　uniformity　index　P-c　nu　and　image　error　I-er　were　set　as　the　single　optimization　objectives,　respectively.　A　L-9(3(4))　orthogonal　design　was　applied　to　analyze　the　weight　of　the　three　structural　parameters　during　the　sensor　design　(electrode　length,　electrode　width,　and　the　number　of　sensor　electrodes),　which　significantly　increased　the　efficiency　of　the　experiments.　A　semi-normal　distribution　was　selected　to　characterize　the　change　trend　of　the　CFIECT.　Finally,　a　comparison　was　proposed.　The　experimental　results　indicated　that　the　sensor　structure　optimized　with　the　CFIECT　could　derive　a　greater　sensitivity　distribution　and　a　better　imaging　reconstruction　results　simultaneously.　It　provides　a　new　optimization　method　for　ECT　sensor　designs.