OBJECTIVE To investigate the effect and mechanism of self-assembled nanoparticles from Shaoyao gancao decoction （SGD-SAN） on the intestinal absorption behavior of its main active components. METHODS SGD-SAN was prepared and characterized. Using an in-situ single-pass intestinal perfusion model in rats， the absorption characteristics of five active components （albiflorin， paeoniflorin， liquiritin apioside， liquiritin， glycyrrhizic acid） from SGD-SAN in the jejunum and ileum were studied， with the absorption rate constant （ K a ） and apparent permeability coefficient （ P eff ） as indicators， and compared with free drugs. In the intestinal segment with optimal absorption， the effects of drug concentration and efflux transporter inhibitors （P-glycoprotein inhibitor verapamil， multidrug resistance-associated protein 2 inhibitor indomethacin， breast cancer resistance protein inhibitor reserpine） on the intestinal absorption characteristics of these components were examined. RESULTS The obtained SGD-SAN exhibited a spherical shape with uniform sizes， an average particle diameter of （155.57±2.65） nm， a polydispersity index of 0.34±0.03， and a Zeta potential of （－9.30±1.12） mV. The average total content of five active components， including albiflorin， was 12.26%， and remained unaffected by enzymatic degradation and intestinal physical absorption. Compared with the free drug group， the five active components in the SGD-SAN group exhibited higher absorption rates in the ileal segment， with significantly elevated K a and P eff values （except for the P eff value of glycyrrhizic acid in the ileal segment） （ P ＜0.05 or P ＜0.01）. Their absorption demonstrated a concentration-dependent trend. In the free drug groups， the absorption of each component was regulated by corresponding inhibitors （ P ＜0.05 or P ＜0.01）； whereas in the SGD-SAN groups， except for albiflorin and paeoniflorin， the absorption of the remaining components was not affected by the inhibitors （ P ＞0.05）. CONCLUSIONS SGD-SAN significantly enhances the intestinal absorption efficiency of active components. The above absorption-enhancing effect may be related to the avoidance of efflux transporter influence and the presence of a mixed absorption mode.