Abstract: This paper considers the impacts of the characteristics of subsidy and supply chain structure on the optimal decision of platform provider, builds the dynamic profit model of platform provider, designs "attraction mechanism" and "competition mechanism", and then solves the optimal trajectory of control variables, state variables and performance indexes. Some experimental tests are carried out and show:(1)the subtler dynamic pricing classification and the more participants being putting into use, the larger optimal profit of platform provider;(2)it is not the case of "the more platform users, the better", because of the attract mechanism and competition mechanism;(3)it shows different pricing trajectories and profit tracks, etc., due to different structures in the supply chain of platform provider;(4)the platform provider should actively provide subsidies to the users, and subsidize the users from the early stage in the implementation of the platform, because the platform provider's profit is directly related to the level of subsidies given to the users.