Addressing the inherent challenges of low recovery rates and difficulties in shale gas extraction, this study investigates the application potential of CO2-enhanced shale gas recovery (CO2-ESGR) coupled with carbon sequestration (CS). Utilizing low-field nuclear magnetic resonance (NMR) technology, we conducted real-time monitoring of methane adsorption and desorption processes within collected shale samples. Through the analysis of T2 spectra and corresponding peak areas, we achieved quantitative differentiation among adsorbed CH4, free CH4 within pore spaces, and free CH4 within fractures. The results demonstrate that within a pressure range of 0.01–10 MPa, the total methane volume increased progressively from 79.4 to 177.83 cm3/g. Following CO2 injection, a significant weakening of the short-T2 signal (representing adsorbed CH4) was observed, accompanied by a concomitant enhancement of the long-T2 signal (representing free-phase CH4). Furthermore, depressurization desorption experiments revealed that CO2 injection increased the methane desorption rate by approximately 10%, while simultaneously facilitating the long-term, stable sequestration of CO2 within the shale matrix. These findings not only validate the mechanism of competitive adsorption, whereby CO2 enhances shale gas recovery, but also highlight the significant carbon sequestration potential of shale reservoirs. Consequently, this research provides a crucial theoretical basis and technical support for advancing both shale gas development and carbon emission reduction strategies