With the rapid development of the world today, the increase of global population, the acceleration of urbanization and the increasing demand for resources have put a certain pressure on the ecological environment. How to balance the ecological and environmental protection while pursuing economic development has become an urgent problem to be solved.The optimization of innovation environment is an important guarantee for green and low-carbon development. Based on the panel data of provinces in China from 2010 to 2020, the fixed effect model and intermediary effect model were constructed to study the influence of innovation environment on carbon emission intensity and its internal mechanism. The threshold regression model was used to study the nonlinear influence of innovation environment on carbon emission intensity. The results show that the innovation environment significantly reduces the carbon emission intensity, and there is regional heterogeneity. Innovation environment indirectly affects carbon emission intensity through the agglomeration of scientific and technological talents. The inhibition effect of innovation environment on carbon emission intensity will be affected by the single threshold effect of the concentration of scientific and technological talents. The higher the concentration level of scientific and technological talents, the stronger the inhibition effect of innovation environment on carbon emission intensity.