The invention provides a method for efficiently preparing cycloastragenol. The method sequentially comprises the following steps of A, fermenting: filling total saponins of radix astragali seu hedysari into a fermentation tank, injecting a buffer solution containing compound enzyme into the fermentation tank until a sample is completely immersed, stirring and then performing catalytic fermentation; B, regulating alkali: after catalysis is ended, regulating fermentation liquid obtained in the step A into an alkali solution, and standing for one hour; C, performing counter-current extraction: pumping the fermentation liquid obtained in the step B and an extraction agent into a counter-current extraction tower for extracting; D, performing vacuum concentration on a mixed solution, which is obtained by extracting, of the cycloastragenol and the extraction agent. The method provided by the invention has the beneficial effects that firstly, a compound enzyme fermentation technology and a continuous counter-current extraction technology are combined for extracting and purifying to obtain high-purity cycloastragenol, and high conversion rate and higher purity of products are realized; secondly, the finishing time of the whole process does not exceed eight hours; the temperature is low in the operation process, so that biological activity of the cycloastragenol is guaranteed; the production efficiency is improved, energy consumption is reduced, and the production cost is reduced by 50 percent or above 50 percent.