The　electrochemical　utilization　of　electron-deficient　methylarenes　for　radical-radical　cross-couplings　remains　very　rare.　Enabled　by　an　umpolung　strategy,　the　unprecedented　electrochemical　cross-coupling　of　electron-deficient　methylarenes　with　aldehydes　was　developed.　The　paired　electrolysis　simultaneously　generated　electron-deficient　benzylic　radicals　and　ketyl　radicals　at　both　electrodes,　which　then　under-went　radical　recombination,　governed　by　polarity　matching　and　persistent-radical　effect　(PRE)　to　afford　functionalized　alcohols　that　are　not　easily　accessible　by　other　methods.　This　protocol　features　catalyst-and　external　redox　agent-free　conditions　and　a　formal　100%　atom　economy.　Mechanistic　studies　support　the　radical-radical　cross-coupling　pathway.