Building a new ecological civilization construction pattern of the human and nature harmonious coexistence, and achieving the economic green transformation and development, which is not only dependent on the promotion of corporate green technology innovation, but also inseparable from the guidance of national ecological rule of law. This paper uses the implementation of the New Environmental Protection Law(NEPL) as quasi-natural experiment, investigating the impact of ecological rule of law on the green technology innovation in heavy polluting companies. The results show that the NEPL significantly improves green technology innovation quantity, quality and efficiency of heavy polluting companies. The mechanism test shows that the NEPL can enhance the green technology innovation of heavy polluting companies by increasing operating costs, raising external financing difficulties, optimizing environmental strategic decision, and improving innovative decision efficiency. The heterogeneity test shows that this effect is more pronounced in the region with weaker development level of legal regulations, the companies with the stronger supervisory demand of the stakeholders and the worse internal governance mechanism. In addition, the disciplinary mechanism of the NEPL plays a dominant role, and the NEPL could strengthen the improving effect of green technology innovation on the sustainability environmental performance of heavy polluting companies.