The invention discloses a method of extracting nervonic acid from malania oleifera, and aims to solve the problems of low product yield, environment pollution and the like in the prior art. In order to achieve the aim, according to the adopted technical scheme, the method comprises the following steps: (1) leaching malania oleifera oil from the malania oleifera by using supercritical CO2 fluid; (2) saponifying the malania oleifera oil to obtain a malania oleifera oil saponified matter; (3) removing the unsaponifiable such as advanced alkanol from the malania oleifera oil saponified matter by using the supercritical CO2 fluid, so as to obtain coarse nervonic acid salt; (4) acidizing, filtering, washing and drying the coarse nervonic acid salt to obtain a nervonic acid product. The nervonic acid product obtained by a supercritical CO2 technique contains the nervonic acid of at least 50 percent, and the preparation process is simple and easy to operate, has the characteristics of low temperature, high efficiency and no pollution, and is suitable for industrialized production.