The invention belongs to the technical field of extraction of plant effective components, and concretely relates to a low-cost and high-efficiency curcumin extraction method. The method sequentially comprises the following steps: taking crushed dry turmeric, carrying out extraction on the crushed dry turmeric by using ethanol, concentrating obtained extraction filtrate, extracting the concentrated filtrate with petroleum ether, re-concentrating the obtained extract, dissolving the obtained concentrate in an aqueous sodium hydroxide solution, extracting the obtained solution with ethyl acetate, and concentrating the obtained ethyl acetate layer to obtain a primary turmeric extract; and dissolving the primary turmeric extract in ethanol, and carrying out high-matching adsorption separation by adopting specially-produced modified attapulgite to respectively obtain a demethoxycurcumin and bisdemethoxycurcumin mixture and highly pure curcumin. The method fully utilizes the structural characteristics of the curcumin and the attapulgite, realizes high matching against the molecular difference, and has the advantages of convenience in operation, no large device demands, high extraction efficiency, low cost, effective separation of the curcumin from the demethoxycurcumin and the bisdemethoxycurcumin, high purity, and realization of industrial production.