Taking the Prunus mira nut as raw material, the oil and protein of were synchronous extracted by aqueous extraction method combined with enzymatic demulsification, the extraction process was optimized by orthogonal tests based on single factor experiment. The main physicochemical indexes of Prunus mira nut oil were determined, and the fatty acid compositions were analyzed by GC. The results indicated that the Prunus mira nut protein yields were(78.13±1.53)%, and oil total yields were(67.79±2.97)%, the optimal oil and protein extraction process were obtained as followed: sample size 150 mesh, liquid-solid ratio 8：1 (mL/g), pH 10, extraction temperature 50 ℃, extraction time 5 h, stirring speed 80 r/min. The physicochemical indexes indicated that Prunus mira nut oil had high physicochemical properties. Twelve fatty acids were detected in Prunus mira nut oil, and the main fatty acids were oleic acid (57.32%), linoleic acid (31.65%), palmitic acid (6.49%) and stearic (2.29%). There were 5 unsaturated fatty acids and the contents were 89.43%, in which there were 3 monounsaturated fat acids with the relative percentage of 57.67%, 2 polyunsaturated fatty acids with the relative percentage of 31.76%.