Financial subsidies and tax incentives play essential roles in the innovation efficiency of enterprises. This paper selects Chinese listed NEV enterprises from 2010 to 2022 as a research sample and investigates various impacts under various circumstances. We find that both financial subsidies and tax incentives can promote the innovation efficiency of NEV enterprises. Compared to financial subsidies, tax incentives are more effective; the interaction between financial subsidies and tax incentives has a weaker impact on the innovation efficiency of NEV enterprises. Both financial subsidies and tax incentives have more potent innovation effects on enterprises with higher financing constraints. In addition, financial subsidies and tax incentives have a stronger innovation efficiency effect on private enterprises than state-owned enterprises. Further research shows that marketization and market distortion affect the innovation efficiency of NEV enterprises. This study provides a new perspective for understanding the effects of financial subsidies, tax incentives, and innovation efficiency of NEV enterprises, and the conclusions and suggestions are relevant references for the government to improve the quality of policy-making.