Inclusive Green growth (IGG) offers an effective alternative to pursue sustainable development. The core of the IGG system lies in the coordination of inclusive, green, and growth subsystems. However, there is little quantitative assessment on IGG based on subsystem collaboration. This paper explores the dynamic coupling IGG nexus in western Yangtze River Delta of China from 2009 to 2018, by using the entropy weight approach (EWA), coupling coordination degree model (CCDM) and obstacle factor diagnostic model (OFDM). The results show that: (1) The integrated approach can allow assessment of the spatiotemporal dynamic coupling nexus of IGG subsystems; (2) At the provincial level, a relatively high IGG performance and a low coupling coordination degree (CCD) of the IGG nexus are seen. The impact of indicators on the coordinated development of IGG can be divided into two stages; (3) At the prefectural level, the cities in which CCD is rising outnumber those it is falling. However, the CCD is also low, and the gap among the regions is getting wider. The obstacles that affect the CCD of cities see a dynamic evolution trend from “inclusive obstacle type” to “inclusive and growth obstacle type” then to “green obstacle type” over the decade.