Mechanochemistry represents an emerging technology that facilitates chemical reactions through the application of mechanical energy. This straightforward technique enhances reaction efficiency, expediting the process in an environmentally friendly, solvent-free manner. Polymers of intrinsic microporosity (PIMs) belongs to a class of polymers characterized by intrinsic microporosity, remarkable processability, and high adsorption capacity, rendering them well-suited for gas-related applications. However, conventional wet chemical synthesis methods of PIM-1 often necessitate substantial solvent usage, leading to significant and enduring environmental impacts. In this study, we present an alternative approach, harnessing green mechanochemical reactions to produce PIM-1. Furthermore, we conducted a comprehensive Life Cycle Assessment (LCA) to compare and simulate the environmental impacts of both wet chemical and mechanosynthesis methods. Our findings indicate the successful qualitative synthesis of PIM-1 through mechanochemistry, resulting in a notable reduction of environmental impacts, approximately 1.5 times less compared to the conventional wet chemical synthesis route. This advancement holds great promise for advancing sustainable and eco-friendly polymer synthesis methods.