Olea europaea leaves were used as raw material for the separation and purification of oleuropein by macroporous resin. The macroporous resin with the best separation effect was screened, and its separation and purification process was optimised, and the degradation kinetics of oleuropein under the conditions of acid, alkali and salt were studied. The results showed that LX-83S macroporous resin had the best separation and purification effect, and the best process was based on the mass concentration 80 g/L of oleuropein in the adsorption solution, the sample flowrate 2 BV/h (BV was the volume of resin bed), and elution with 3 BV volume fraction of 50% ethanol. After further crystallization, the Olea europaea leaf extract was an off-white powder with good water solubility and the mass fraction of oleuropein was higher than 70%. The hydrolysis of oleuropein was accelerated under acidic conditions, and the rate of degradation decreased under low alkaline and salt conditions.