As global trade governance increasingly incorporates environmental standards, mechanisms such as the EU Carbon Border Adjustment Mechanism (CBAM) create growing compliance pressures and cost burdens for China’s manufacturing sector. This study examines the transmission mechanisms through which green trade barriers (GTBs) affect firm-level innovation and competitiveness. The analysis identifies several structural constraints that may limit the effectiveness of innovation-based adaptation: an energy system constraint associated with the high carbon intensity of the national power grid; a resource-allocation dilemma in which short-term compliance costs may reduce long-term R&D investment; disparities in carbon accounting and digital capabilities; and a strategic tendency toward product-level compliance rather than deeper process-oriented decarbonization. In response to these constraints, this study proposes an implementation framework structured around an Actor–Tool–Timeline matrix. Policy recommendations include promoting green power trading through reforms in energy-use allocation, expanding transition finance to ease adjustment pressures on SMEs, and developing public digital platforms for carbon verification. Furthermore, the study argues that sustained long-term competitiveness depends on stronger indigenous innovation capacity and greater participation in international rule-making, while drawing on the principle of common but differentiated responsibilities (CBDR) to respond to emerging forms of environmentally driven trade restriction.