Abstract: To address the challenges associated with tight conglomerate reservoirs, including complex pore throat structures, poor mobilization of crude oil in micropores, and rapid production decline in conventional huff-and-puff development, this study investigates the synergistic effects of nano-emulsion and supercritical CO₂ (SC-CO₂) huff-and-puff on oil mobilization in multi-scale pore throats. Tight conglomerate core samples from the same reservoir interval were selected. High-pressure mercury intrusion and nuclear magnetic resonance (NMR) T₂ spectrum were combined to calibrate the pore-throat structures. Comparative experiments were then carried out, including depletion development, multiple cycles of nano-emulsion and formation water huff-and-puff, followed by SC-CO₂ huff-and-puff. By continuously monitoring the changes in NMR T₂ spectra throughout the entire cycle, the fluid mobilization efficiency and recovery contribution in different pore-size ranges >10μm were quantitatively analyzed. During the depletion stage, oil is mainly produced from medium-large pores (>1 μm) with sound hydraulic communication, while the recovery from micropores is lower than 15%, resulting in an overall recovery of 11%-12% only. Nano-emulsion huff-and-puff improves the mobilization efficiency in 0.1-10 μm pore-throat range by approximately 5%-25% compared with formation water, and the overall recovery reaches 53% after three cycles. Subsequent SC-CO₂ huff-and-puff further enhances oil mobilization across all pore throat sizes,with particularly significant effects in micropores and large pores. After three cycles, the overall mobilization efficiency approaches 90%, which is about 14% higher than that of pre-treatment with formation-water. The results indicate that nano-emulsion pre-huff-and-puff combining with subsequent SC-CO₂ huff-and-puff exhibits favorable compatibility, which promotes the further mobilization of residual oil from large pores to micropores, and increases the overall recovery by 67%. This combined approach therefore has positive implications for improving crude oil mobilization in the micropores of tight conglomerate reservoirs.