The invention provides a method for extracting steviol glycosides in stevia rebaudiana by simulated moving bed chromatography, which belongs to the purification method of natural plant effective components. In the process of extracting steviol glycosides, column chromatography purification is a key step, but the amount of resin is large, the utilization rate is low, the regeneration cycle is long, and a large amount of waste water is generated, most of which are batch operations. The SMBC separation technology using C18 as the stationary phase in the present invention can purify steviol glycosides from stevioside crude extracts in a large-scale, robust, continuous, automatic and efficient manner, and the stationary phase and mobile phase can be used repeatedly, reducing the cost of purification and belonging to green Environmentally friendly separation process. Combining water leaching and chromatographic impurity removal, water consumption and energy consumption are reduced, flocculation and impurity removal are not required, stationary phase does not need special regeneration, waste water discharge is reduced, and the process is simple.