At present, the integration and development of scientific and technological innovation and industrial innovation, along with their same-frequency resonance, are regarded as the two wings for the development of new productive forces. A comprehensive evaluation system was constructed based on the entropy method and the coupling coordination degree model to measure the level of integrated development of scientific and technological innovation and industrial innovation in 31 provinces of China (Due to the lack of data, the statistical data mentioned here do not include the Hong Kong Special Administrative Region, the Macao Special Administrative Region and Taiwan Province.) from 2012 to 2023. Then, the Dagum Gini coefficient decomposition, Kernel density estimation, Moran's I index, and spatial convergence model were used to explore the regional differences, spatiotemporal evolution, and convergence characteristics of the integration development level of the two. It is found that the level of integration of scientific and technological innovation and industrial innovation in China is generally increasing year by year, showing spatial characteristics of "high in the east and low in the west". The regional gap in the integration development level showed a rising trend. The gap within the eastern region was the largest, and the gap between the eastern and western regions was also the largest. The overall difference mainly came from regional disparities. The overall integration level changed from relative dispersion of low values to high concentration of high values, the imbalance increased obviously, and multi-polarization characteristics appeared in the central, western, and northeastern regions. The positive spatial aggregation effect is significant, and absolute β convergence and conditional β convergence existed in the whole country and the four major regions. Consequently, the current situation of the integration of scientific and technological innovation and industrial innovation in China is clarified. Efficient allocation of innovative development resources, optimization of the economic structure, and enhancement of development coordination, and strong support for the construction of a new development pattern are thus provided.