Clarifying the driving effects of the Major Function-Oriented Zones strategy (MFOZs) on regional carbon emission patterns and deciphering its "gray-box" transmission mechanism served as the basis for constructing a regional "dual-carbon" policy framework. This paper took the Sichuan-Chongqing region as an empirical case, systematically employing the Difference-In-Differences (DID), the Mediation Effect Model (MEM), and the Spatial Difference-In-Differences (SDID) in an integrated approach?to dissect the?Major Function-Oriented Zones strategy's?carbon emission pattern-driving effects?precisely?and?to uncover?its?underlying?transmission modes. The key results showed that: (1) Over the period?from 2005?through?2020, total carbon emissions in the Sichuan-Chongqing region increased by 83.0%, with the growth rate gradually decelerating over time. The spatial pattern remained stable, characterized by "higher emissions in the east and lower in the west," with emission scale decreasing radially outward from the Chengdu-Chongqing dual-core region. This carbon emission distribution pattern closely corresponded with the region’s functional zoning. (2) The Major Function-Oriented Zones strategy exhibited distinctly differentiated driving effects on regional carbon emission patterns, demonstrating a?strong synergy with?the designated?functional orientations. Urbanization Development Zones (UDZs) showed statistically significant positive drivers of carbon emissions, while both Main Agricultural Production Zones (MAPZs) and Key Ecological Function Zones (KEFZs) exhibited statistically?marked negative?driving?effects?on carbon emissions. (3) The three functional zones exhibited differentiated policy spatial transmission mechanisms. Urbanization Development Zones demonstrated positive incentive effects promoting carbon growth through four policy channels including population aggregation, industrial aggregation and urban expansion, which promoted carbon emission growth. In contrast, policy transmission channels in Main Agricultural Production Zones lacked clear direction, yet industrial access restrictions and urban development controls led to a declining trend in carbon emissions. Key ecological functional zones, however, displayed overall negative incentive effects through five key channels such as population relocation, industrial curbs, and urban contraction, thereby resulting in either low-rate carbon accumulation or dilution. (4) Carbon emission increments across the region showed a converging trend, with the core carbon emissions source centers shifting toward Urbanization Development Zones within the Chengdu-Chongqing economic circle. Concurrently, Urbanization Development Zones and Main Agricultural Production Zones exhibited carbon source attributes that were?far stronger than?their?carbon sink attributes, while Key Ecological Function Zones generally demonstrated pervasive carbon emission dilution patterns. (5) Spatial spillover effects were evident in the regional carbon emissions. Urbanization Development Zones stimulated carbon emissions in neighboring areas, whereas both Main Agricultural Production Zones and Key Ecological Function Zones exerted suppressed influences?on emissions in adjacent regions.