The invention provides a blend oil, a preparation method and application thereof. The blend oil, counted in 100 parts by weight, comprises 0.1-5 parts of phytosterol ester, 0.01-5 parts of microalgae DHA and 90-99.8 parts of other oil components; the other oil components are sorted from three or more than three of soybean oil, colza oil, maize oil, sunflower oil, peanut oil, sesame oil, tea seed soil, palm oil, cottonseed oil, rice bran oil, olive oil, safflower oil, linseed oil, cannabis oil, pig tallow, beef tallow, or microalgae oil.