In recent years, the empowerment behavior of e-commerce platforms to supply chain partners has increased rapidly, which has important influence on the operational decisions and benefits of supply chain members. In the scenario of e-commerce platforms' brand empowerment behavior, this paper studies the incentive mechanism considering vertical channel conflicts among supply chain members in a supply chain, which composes of one e-commerce platform, one retailer and one supplier of other channel. Under the condition of information asymmetry, it also discusses how the e-commerce platform as a core enterprise can use the mechanism design method to identify the quality of products ordered by the retailer from the other channel supplier. The results show that the e-commerce platform can increase the number and proportion of products ordered by the retailer from e-commerce platforms by setting incentive mechanism under the pooling strategy and the separating strategy. If the retailer has a high probability of ordering products from other channel suppliers with a higher product quality, the e-commerce platform should adopt separating strategy, which is more conducive to increasing the total order volume of the retailer, otherwise it should adopt the pooling strategy. The expected profit of e-commerce platforms under the separating strategy is greater than that of the pooling strategy, and both are greater than the case where no incentive mechanism is provided to the retailer.