Abstract: Acer truncatum seed oil (ASO), as a new resource food, contains a large amount of valuable fatty acids (especially nerve acids). In order to improve the quality characteristics and storage stability of ASO, refining ASO obtained using subcritical extraction to remove phospholipids, peroxides, and free fatty acids. In this paper, the extraction process of subcritical extraction ASO was optimized, and the crude oil was degummed and refined by membrane separation technology. Using membrane flux, degumming rate, iodine value, peroxide value and acid value as indicators, ceramic membranes with different pore sizes and polyethersulfone membranes with different molecular weights were screened. The effects of membrane retention of molecular weight, temperature and pressure on membrane flux were investigated, and the optimal process parameters for refining ASO were determined through response surface methodology. An analysis of the fatty acid composition was conducted using gas chromatography-mass spectrometry both before and after refining. The results showed that, when the molecular weight of the polyethersulfone membrane was 100 kD, the temperature was 44 ℃, the pressure was 1.9 MPa, ASO degumming rate was 86.73%, the flux was 12.51 L/m²·h, the iodine value was 116.93 g/100 g, the peroxide value was 0.06 g/100 g, the acid value was 3.66 g/100 g, and there was no significant loss of fatty acid content compared to crude oil. The results showed that degumming by membrane separation is an effective method to improve the quality of oil, so this study can provide technical support for the production of high-quality Acer truncatum seed oil.