Making　environmental　regulation　(ER)　in　line　with　local　development　reality　is　the　key　to　promoting　regional　coordinated　development.　Current　research　mainly　concentrates　on　the　overall　effect　of　ER　or　the　policy　effect　of　some　specific　regulations.　In　reality,　the　ERs　are　not　always　one-size-fits-all,　and　the　evaluation　of　the　biased　ER???s　effect　is　mostly　overlooked.　This　paper　takes　the　biased　energy-saving　policy　(BESP)　of　13th　Five　Year　Plan　as　an　example　and　identifies　the　impact　of　the　BESP　on　enterprises???　total　factor　productivity　(TFP)　based　on　a　Difference-in-Difference　model.　Our　results　suggest　that　the　BESP　has　significant　promotion　on　the　enterprises???　TFP.　When　considering　the　heterogeneity　of　enterprise　and　industrial　characteristics,　it　can　be　found　that　large-scale,　state-owned　enterprises　as　well　as　enterprises　with　capital-intensive　show　more　significant　promotion　effect　from　the　BESP.　Moreover,　enterprises　in　high-energy　consumption　and　low-tech　industries　also　reveal　more　significant　policy　effect.　Further,　the　results　of　the　mechanism　analysis　indicate　that　the　BESP　promotes　the　enterprises＇　TFP　mainly　through　enhancing　technical-focused　investment　preference　and　narrowing　technical　gap　within　the　industry.　Our　research　fills　the　gap　in　the　study　of　biased　ER,　which　provides　a　new　orientation　for　realizing　the　carbon　neutrality　goal.