In　this　study,　synergic　alkali　catalysts　(NaOH　+　NaAlO2)　and　Ni/ZrO2　were　used　for　microwave-assisted　lignin　depolymerization.　The　effect　of　temperature,　alkali　dosage,　Ni/ZrO2　dosage,　and　solid-to-liquid　mass　ratio　was　studied　to　improve　the　catalytic　degradation　efficiency　and　the　yield　of　phenolic　compounds.　The　results　showed　that　more　than　87.7%　of　lignin　was　converted　and　more　than　0.582　mmol　g(-1)　total　phenolic　hydroxyl　concentration　was　obtained　at　180　degrees　C.　Furthermore,　the　characterization　results　of　FT-IR,　UV-VIS,　TG-DSC,　GPC　and　H-1-NMR　clearly　demonstrated　that　the　synergistic　system　of　an　alkali　and　Ni/ZrO2　effectively　improved　the　degradation　efficiency　and　inhibited　the　formation　of　char,　and　resulted　in　a　series　of　compounds　with　low　molecular　weight　(＜1000).　In　addition,　the　GC-MS　results　showed　that　the　selectivity　of　the　phenolic　monomer　product　(68.2%)　significantly　improved　after　degradation.　The　lignin　depolymerization　mechanisms　involved　demethoxylation,　dealkylation　and　decarbonylation.