Using　panel　data　on　China＇s　carbon-covered　listed　enterprises,　this　study　employs　the　Poisson　pseudo-maximum　likelihood　with　high-dimensional　fixed　effects　(PPMLHDFE)　approach　to　investigate　the　impact　of　the　carbon　emissions　trading　(CET)　policy　on　firms＇　green　technology　innovation.　A　novel　categorization　is　proposed　to　classify　the　enterprises　in　carbon-covered　industries　into　CET-included　and　non-CET-included　groups.　Results　show　that　China＇s　CET　policy　plays　a　vital　role　in　green　technology　innovation,　with　a　stronger　positive　effect　on　CET-included　enterprises.　Furthermore,　heterogeneity　exists　among　eight　carbon-covered　industries.　The　green　technology　innovation　of　enterprises　in　the　power　and　petrochemical　industries,　particularly　the　CET-included　ones,　is　stimulated　by　the　CET　policy.　However,　it　inhibits　green　technology　innovation　in　the　aviation　and　chemical　industries　and　plays　no　role　in　other　industries.　Additionally,　the　effect　exhibits　heterogeneity　across　pilot　areas.　It　is　positive　in　Hubei　and　Tianjin,　negative　in　Chongqing　and　Shanghai,　and　ineffective　in　Beijing,　Guangdong,　and　Shenzhen.　Finally,　the　effect　of　the　CET　policy　on　green　technology　innovation　is　stronger　for　state-owned　enterprises　than　for　non-state-owned　ones.