System and method for preparing and selling a customized cosmetic in shop

A system and a method for preparing/selling customized cosmetics in a shop are provided to sell the customized cosmetics in a complete product type by mixing a base product and a skincare product based on a skin diagnosis result of a customer visiting the shop, and filling the mixed product to a container. A shop terminal(10) measures skin characteristics of the customer by including an oil/humidity measurer(11) and a skin camera(12). A calculator calculates an index for various kinds of types by receiving skin measurement information of the shop terminal through the Internet(20). A server(30) outputs a prescription displaying the kinds of main materials to be mixed based on the calculated index. A cosmetic preparation system(40) includes a base product kit prepared to each skin type according to an oil/humidity difference and a skincare product kit added to the base product to improve skin troubles. The cosmetic preparation system makes the complete cosmetic product by selectively mixing the base product and the skincare product according to the prescription.