The present invention relates to a method for preparing cannabidiol by separation and purification using high-speed countercurrent chromatography, comprising: alcohol extraction and water precipitation, adsorption with a macroporous resin, and high-speed countercurrent chromatography separation. The present invention separates and obtains high-purity cannabidiol from industrial hemp flowers or leaves, while at the same time removing the psychotoxic component tetrahydrocannabinol by combining a macroporous resin chromatographic column with a high-speed countercurrent chromatograph, and optimizing process parameters, and the solvent used therein being environmentally friendly, leaving no residues, having low cost and being recyclable. Therefore, the method is suitable for industrial production.