To　develop　novel　polymerizations　capable　of　manipulating　low　molecular　weight　distribution　(D)　through　novel　polymerization　species　rather　than　radical,　anionic,　or　cationic　species　is　highly　desirable　and　challenging,　which　will　enable　polymer　chemistry　with　a　new　polymerization　mode　and　synthetic　route.　Grignard　reagent　mediated　alkene　polymerization　is　generally　regarded　as　anionic　polymerization　that　is　not　applicable　for　nonpolar　monomers　like　styrene　(St).　Here,　the　turbo-Grignard　reagent　mediated　polymerization　of　St　is　demonstrated　to　exhibit　intriguing　all-in-one　characteristics　of　covalent-anionic-radical　polymerization.　Under　mild　conditions,　polystyrenes　with　narrow　molecular　weight　distribution　can　be　obtained　with　over　99%　monomer　conversion　by　using　a　series　of　turbo-Grignard　reagents　(RMgXmiddotLiCl)　as　initiators,　including　alkylMgClmiddotLiCl,　BnMgClmiddotLiCl,　and　allylMgClmiddotLiCl.　In　comparison　with　traditional　Grignard　reagent　mediated　reactions　and　polymerizations　exhibiting　zero　tolerance　with　reactive　hydrogen,　this　turbo-Grignard　reagent　mediated　polymerization　exhibits　compatibility　with　reactive　hydrogen　under　mild　conditions　and　expands　the　library　of　polymerization　with　an　intriguing　turbo-Grignard　reagent　mediated　all-in-one　covalent,　anionic,　and　radical　polymerization　mode.