The invention provides a method for separating and purifying kainic acid through controllable multichannel electroosmosis, which comprises the following steps of: drying Caloglossa leprieurii or digenea, and crushing into small particles; refluxing and cooking the particles by using ethanol, and mixing filtrate; performing ultrafiltration on the filtrate to remove particle impurities; removing salts, polysaccharide compounds and other impurities from the filtrate through controllable multichannel electroosmosis; further separating and purifying by using an ion exchange resin column to remove impurities such as amino acid with similar properties to the kainic acid; and performing vacuum drying and crystallization to obtain the kainic acid.