This paper aims to study storage location assignment of RMFS and propose an assignment mechanism model based on the Dutch auction strategy to improve the picking efficiency of RMFS. The Dutch auction model was es-tablished to gradually adjust the SKU of the designated area through the turnover rate to achieve a reasonable match between the demand model and the inventory structure of SKU, and assign matching degree as the expected index. Comparing with the random assignment model, it was found that the average picking distance of the picking route based on the Dutch auction under the condition of different warehouse size, demand skewness, order size, etc. decreased by 21.15%, and the working time decreased by an average of 20.57%. Compared with the traditional assignment method, the assignment mechanism model proposed in this paper significantly shorten the picking distance or time and greatly improve the picking efficiency of the RMFS of online retail enterprises.