The invention discloses an on-line cake customization method and system. The method comprises the following steps: establishing a commercial tenant database, wherein the commercial tenant database comprises a commercial tenant logo and at least one customization item provided by a commercial tenant; according to the commercial tenant database, sending a cake customization request to a service side by a user side, wherein the cake customization request comprises at least one customization item selected by a user; and receiving the cake customization request sent from the client side by the service side, inquiring a preset price database to obtain price corresponding to the customization item selected by the user, and returning the price of the customized cake to the user side, wherein the price database comprises an association relationship between the customization item and the price. By use of the method, through the setting of customization, a purpose that the styles of the customized cakes can be increased is achieved according to a cake dough, side decoration, top surface decoration or single decoration selected by the user, and meanwhile, the demands of the user for cake individuation can be met according to the selection of the user for the customization item.