With the deep integration of supply chain with Internet and Internet of things, it is an important way for enterprises to win market competition and seek sustainable development to develop green new products through external green supply chain integration (GSCI). This study established a unified research framework of external GSCI, knowledge spiral (KS), green new product development (NPD), and top management’s environmental awareness (TMEA). Structural equation modeling and analytic hierarchy process are used to explore the mechanism of the established research framework. The research results of this paper are as follows: (i) Green supplier integration (SI) and green consumer integration (CI) have significant positive effects on green NPD speed (GS), green NPD quality (GQ), and KS, and KS has a significant positive effect on GS and GS, respectively. Compared with green CI, green SI has a greater impact on KS, GS, and GQ. In addition, compared with GS, KS has a greater impact on GQ; (ii) KS has a significant partial mediating effect in the relationship between green CI, GS, and GQ. Compared with GS, KS has stronger mediating effect between green CI and GQ. Compared with green SI, the equivalent KS capability is more significant in integrating green customer information; (iii) TMEA has a significant moderating effect on the relationship between KS, and GQ and has no significant moderating effect on the relationship between KS and GS. Future research will analyze the mediating effect of the four dimensions of KS in the relationship between external GSCM and the green NPD speed and green NPD quality.