The invention belongs to the technical field of vegetable oil and particularly relates to blend oil with a healthcare function and a preparation method thereof. The blend oil comprises the following components of rice bran oil, linseed oil, poppyseed oil, purple perilla seed oil and chia oil. As an optimal technical scheme, the blend oil is further prepared from, by weight, 5-10 parts of pumpkin seed oil, 3-5 parts of pine-seed oil, 2-3 parts of borage oil, 3-5 parts of olive oil, 3-5 parts of semen juglandis oil, 2-3 parts of safflower oil, 3-5 parts of grape seed oil, 3-5 parts of apple seed oil, 3-5 parts of pomegranate seed oil and 3-5 parts of peony seed oil. On the basis of discharging cholesterol in blood, the blend oil can stop a body from synthesizing cholesterol, reduce fatty liver and deposition of internal fat, reduce low-density lipoprotein cholesterol in blood and improve the level of high-density lipoprotein cholesterol, and has a positive effect of restraining and preventing hypertension, hyperlipidemia, atherosclerosis and other heart and cerebral vessel diseases.