Abstract: The online secondary platform (referred to as secondary platform, such as secondary e-commerce platform, secondary ticketing platform) provides a non-official trading channel between sellers and consumers. In order to study the impact of the secondary platform on the brand enterprise and consumers, the demand models of ordinary commodities with sufficient inventory and limited commodities under the dual channel mode of official channel and secondary platform are established respectively. Price-dependent function is used to model the demand of the ordinary commodities and utility function is used to model the demand of the limited commodities. The results show that for ordinary commodities, the secondary platform provides a distribution channel for the brand enterprise to realize pricing differentiation so as to increase the total demand. The purchase cost of consumers with low consumption level is also reduced. For limited commodities, the existence of secondary platform increases the speculation of scalpers and redistributes the limited commodities among different types of consumers. Finally, theoretical suggestions for the regulatory strategies of the regulatory department on the secondary platform are proposed.