The　Green　industrial　policy　is　implemented　to　promote　the　coordinative　development　of　the　environment　and　industry,　while　there　has　been　limited　research　involved　in　the　policy　effect　evaluation.　Taking　China＇s　Green　Manufacturing　Engineering　Implementation　Guide　(GMEIG)　released　especially　for　manufacturing　industry　in　2016　as　a　quasi-natural　experiment,　this　paper　identifies　the　policy　effect　on　the　total　factor　productivity　(TFP)　of　manufacturing　enterprises,　and　the　mechanisms　and　heterogeneities　are　further　evaluated.　The　baseline　results　show　that　green　industrial　policy　has　significant　promotion　on　the　TFP　of　manufacturing　enterprises.　The　mechanism　is　analyzed　from　two　perspectives,　including　incentive　effect　and　supervision　effect.　Moreover,　mediating　effects　of　different　time　points　of　government　subsidy　are　investigated　within　the　incentive　effect.　The　results　reveal　that　GMEIG　promotes　the　TFP　of　manufacturing　enterprises　through　incentive　effect　and　the　promotion　on　enterprises＇　TFP　mainly　benefits　from　government　subsidies　afterwards　rather　than　government　subsidies　beforehand.　When　considering　the　heterogeneity　at　regional,　industrial　and　enterprise　levels,　the　policy　effect　is　more　significant　in　non-state-owned　enterprises,　as　well　as　enterprises　with　smaller　scale.　What　is　more,　market　competitiveness　is　conducive　to　the　promotion　on　enterprises＇　TFP,　while　current　level　of　green　preference　fails　to　positively　moderate　the　policy　effect.　This　study　provides　theoretical　and　empirical　support　for　the　construction　of　green　industrial　policy　and　further　facilitates　China＇s　green　development.