The amphiphilic polymer can spontaneously form self-aggregating nano-sized micelles having a core-shell structure in aqueous system， which is increasingly attracting attention and recognition for its ability to improve the solubility of hydrophobic substances. In this paper， oat β-glucan was used as raw material， and it was esterified and modified with hydrophobic saturated fatty acid-stearic acid to obtain amphiphilic oat β-glucan ester. By investigating the effect of the amount of stearic acid acyl imidazole added， the reaction temperature and the reaction time on the substitution degree of the product， the substitution degree of the reaction product is the largest， which could reach 0.133， when the stearic acid acyl imidazole amount was 6.50 mL， the reaction temperature was 90 ℃， the reaction time of the whole system was 5.0 hours. The obtained products were characterized by Fourier transform infrared spectroscopy （FTIR） and nuclear magnetic resonance spectroscopy （NMR）. The obtained results all proved the successful preparation of amphiphilic oat β-glucan ester. After studying its related physical properties， further in vitro cytotoxicity test found that oat β-glucan stearate ester （OGE） is not cytotoxic. All the above results suggest that OGE can be used as a new carrier material for hydrophobic bioactive substances， which can effectively solve the current situation of low bioavailability of most hydrophobic active substances. Therefore， it will have broad development prospects in many fields such as medicine， food， and chemical industry.