1,　4-Bis[2-(3,　4,　5-trimethoxyphenyl)vinyl]　benzene　(HPV)　is　one　of　organic　conducting　materials.　The　effect　of　electro-Wittig　synthesis　reaction　conditions,　including　the　material　of　the　electrode,　the　reaction　current,　the　type　of　solvent,　the　concentration　of　reactants,　the　reaction　temperature　and　so　on,　on　the　yields　and　reaction　selectivity　of　the　three　isomers　of　HPV　is　studied.　The　experimental　results　show　that　the　use　of　mixed　solvents　greatly　benefits　the　formation　of　cis-isomer　in　the　electrosynthesis　of　HPV.　If　a　mixed　solvents　of　methanol　and　pyridine　was　used,　about　47%　cis-cis,　48%　cis-trans　and　5%　trans-trams　isomers　were　obtained　in　90%　yield　with　a　cis　:　trams　ratio　of　about　2.4:1.　The　possible　reaction　mechanism　is　also　discussed.