Corn starch and oleic acid were treated with microwave-assisted lipase catalysis under low moisture conditions. The effects of the treatments on the interaction, structural changes and binding mechanism between corn starch and oleic acid were investigated. After microwave treatment, some of the α-1,4 glycosidic bonds in corn starch were broken, causing linear starch to precipitate. The content of amylose increased from 23.40 % to 51.66 %. The structure facilitates an increase the degree of complexation. The complex index of corn starch-oleic acid complexes was 43.2 % and that of corn starch-oleic acid conjugates was 57.7 %. The structures of samples were studied using by Raman spectroscopy, X-ray diffraction, nuclear magnetic resonance carbon spectrum, and scanning electron microscopy. The results indicated that the esterification reaction promoted the complexation reaction, creating a more stable structure that was less prone to disintegration. Among them, the starch-oleic acid conjugated compounds' resistant starch content was the highest at 69.12 %. The thermal stability of the corn starch oleic acid conjugate has also increased compared to the corn starch-oleic acid complex, with ΔH increased from 26.77 % to 31.33 %. The present study confirmed that the microwave combined with lipase catalysis could produce resistant starch with a more stable structure.