China's economy is in a critical period of growth dynamics switching as the growth rate shifts to a high-quality development stage. Based on China's inter-provincial panel data from 2000 to 2022, focuseing on the issue of China's economic growth momentum switching, the spatial and temporal evolution of economic growth momentum switching and the "double threshold" effect was explored. The results show that productive labor, R&D labor, production inputs, and R&D inputs significantly contribute to China's economic growth. China's growth momentum switching has experienced the "productive labor and production inputs", and "R&D labor and production inputs", and "R&D labor and production inputs", and "R&D labor and R&D input". The spatial and temporal evolution of China's economic growth dynamics has regional heterogeneity and time heterogeneity, and there are significant differences in economic growth dynamics between different regions and time periods. the switching of China's economic growth dynamics is subject to external constraints, and there exists a "double-threshold" effect. At the same time, it uses the main experiment to add control variables before and after the comparison, bilateral shrinking tails, excluding the impact of epidemics and propensity score matching to conduct robustness tests, and finds that the empirical results are robust. This study helps to understand the mechanisms, paths and constraints of switching economic growth dynamics, and provides a reference basis for formulating corresponding policies and strategies.