Mechanochemistry has emerged as a pivotal strategy for advancing sustainable and green polymer synthesis, addressing critical challenges in reducing solvent waste, energy consumption, and environmental toxicity. At its core lies the fundamental scientific challenge of efficiently coupling mechanical force with controlled radical polymerization mechanisms while developing synergistic strategies to overcome kinetic and thermodynamic limitations. This presentation introduces a groundbreaking approach centered on tandem mechanoactivation, designed to achieve high-efficiency mechanical energy transfer and precise spatiotemporal regulation of multi-component controlled radical polymerization. First, we will elucidate a novel radical generation mechanism driven by tandem mechanoactivation. This process leverages sequential mechanical energy inputs to initiate polymerization at significantly reduced activation energies, establishing a low-energy mechanochemical platform. Remarkably, this system operates efficiently under solvent-free conditions and is inherently air-tolerant, enabling the precise synthesis of well-defined polymers with tailored molecular weights and narrow dispersities—without the need for volatile organic solvents or inert atmospheres.Second, we will present a solventless mechanochemical strategy for controlled copolymerization, specifically resolving persistent kinetic challenges such as component immiscibility and diffusion limitations that plague conventional solution-based reactions. By eliminating solvent-mediated barriers, this approach facilitates the controlled synthesis of functional polymer nanocomposites, integrating nanomaterials (e.g., graphene, cellulose nanocrystals) directly into the polymer matrix. The resulting composites exhibit enhanced functional properties—including mechanical and electromagnetic performance—while aligning with green chemistry principles.