Partial multi-homing is one of new researching directions of two-sided markets. This article classified the types of two-sided markets based on characteristics of the behavior of users, and then considered a model of two-sided markets under the situation that competing platforms are different and users are partially multi-homing. The result shows that partial multi-homing decreases the price and profits of platforms, and the profits of platforms are highest when users single-homing, thus platforms have internal motivation to prevent users to be multi-homing. Differentiation between platforms increases profits of them. The results of this article are useful to enact pricing and competition strategies for two-sided markets enterprises, and also can be used to make policies of industrial regulation as academic evidence.