Low-carbon　technology　innovation　(LCTI)　is　key　to　achieving　energy　conservation　and　emission　reduction.　As　the　main　body　of　carbon　emissions,　accelerating　the　promotion　of　energy　enterprises’　LCTI　is　urgently　needed.　Based　on　the　importance　of　horizontal　coopetition　and　government　regulation　for　enterprises’　LCTI,　this　paper　establishes　a　tripartite　evolutionary　game　model　of　local　government　and　two　homogeneous　energy　enterprises　to　clarify　their　dynamic　behavior　strategies.　Furthermore,　through　numerical　simulation,　a　sensitivity　analysis　of　the　effect　of　the　main　parameter　changes　on　all　parties’　evolution　is　carried　out.　Moreover,　we　obtained　the　accurate　optimal　value　of　S&P　(subsidies　and　penalties)　by　using　a　combination　of　random　jumping　and　L-BFGS-B　method.　The　findings　indicate　that　(i)　increasing　the　initial　willingness　of　government　and　enterprises　can　facilitate　faster　system　evolution　towards　optimal　state.　Early　governmental　intervention　can　be　beneficial　in　preventing　negative　behavior　of　enterprises.　(ii)　There　exists　optimal　range,　and　even　optimal　level,　for　government　S&P,　with　penalties　being　more　effective　than　subsidies　in　promoting　LCTI.　(iii)Low　coopetition　is　ineffective　while　the　intensity　of　coopetitive　relationship　is　positively　correlated　with　its’　effect.　(iiii)　Small-scale　enterprises　are　more　sensitive　to　changes　in　S&P　measures　and　coopetition　relationships.　©　2023　Elsevier　Ltd