Phospholipid, medium-chain fatty acid triglyceride, glycerol, lipase, and phospholipase are mixed according to a weight ratio of 100:1-80:0-20:0.1-15:0.1-15. Then, the mixture proceeds dephosphorylation and interesterification reactions under a temperature of about 30-90℃. Next, distillation is performed to remove the phospholipids, triglycerides, and free fatty acids to obtain edible oil containing medium-chain fatty acid diglycerides in high concentration.