The late-stage production of the J reservoir in the Xinjiang Oilfield is characterized by low output, insufficient energy replenishment, and low recovery rates. In the early stage, the single CO2 huff-n-puff and energy enhancement tests of surfactant have been carried out, and there are problems of injection medium channeling and low energy enhancement efficiency. Consequently, research on the applicability of CO2-surfactant composite huff-and-puff technology was initiated. Targeting the J reservoir, suitable surfactant systems were selected through laboratory experiments focusing on reducing oil–water interfacial tension, wettability alteration, and foam generation. Following this, physical simulation experiments of huff-and-puff processes on natural cores were conducted to explore the potential for enhanced oil recovery (EOR) and pore utilization patterns using different media (CO2 and CO2-surfactant composite). Experimental results indicate that under simulated reservoir conditions, the YYC surfactant selected can reduce the oil–water interfacial tension to 5.83 × 10−3mN/m at an effective concentration of 2000 ppm, the foam foaming volume to 550 mL and the eluting half-life to 160 s under CO2 environment, and the wetting contact angle can be reduced from the initial 111.19° to 37.26°. At the same time, the imbibition displacement efficiency can reach 20.75%, demonstrating excellent reservoir adaptability. The physical simulation experiments on natural cores reveal that compared to single-phase CO2 huff-and-puff, the CO2-surfactant composite huff-and-puff technique yields a 12.28% higher recovery rate. Analyzing the NMR T2 time spectra, the composite huff-and-puff process not only efficiently mobilizes oil from large and medium pores but also displaces a portion of the oil from small pores. These findings provide valuable technical insights for enhancing oil recovery in unconventional reservoirs.