Under the background of the new trend of scientific and technological revolution, digital transformation is an effective path for enterprises to achieve sustainable development. The application of digital technology will have a great impact on the production and innovation mode of enterprises. Based on the pilot work of “industrialization and informatization” implemented by the Ministry of Industry and Information Technology of China in manufacturing enterprises across China, this paper regards this event as a quasi-natural experiment. By matching the patent data of the State Intellectual Property Office with the data of listed companies, the multi-stage DID model is used to identify the inter-regional collaborative innovation effect of digital transformation.

The empirical results show that compared with manufacturing enterprises that did not carry out the trial operation of the integrated information and industrialization management system, the number of joint patent applications in different regions of pilot enterprises has increased significantly; The impact of digital transformation on enterprises' inter-regional collaborative innovation is more obvious in underdeveloped cities, low market competitiveness, high proportion of senior executives with R&D background and state-owned enterprises. The mechanism analysis shows that the digital transformation mainly affects the inter-regional collaborative innovation of enterprises through compressing the space-time distance and business process reengineering; Shortening the space-time distance can reduce the search and communication cost of enterprise collaborative innovation; Process reengineering can enable enterprises to carry out collaborative innovation based on core competitiveness. Further research shows that the cooperative innovation effect brought by digital transformation has influence on all types of patents; At the same time, digital transformation breaks the restriction of geographical factors on enterprises' selection of knowledge proximity subjects, which is conducive to inter-regional collaborative innovation between enterprises and different knowledge subjects.

Based on the empirical results, this paper puts forward some policy suggestions, such as grasping the opportunities of enterprise digital transformation, strengthening the construction of digital scene, reducing the cost of enterprise cooperation, and promoting enterprise collaborative innovation.