E-commerce has a strong development momentum in recent years, and the oligopoly structure trend of e-commerce platforms has become more and more obvious. At the same time, the “Pick One of Two” behavior of e-commerce platforms has been constantly performed in various fields. Although “Pick One of Two” behavior has existed for many years in China, it has not been effectively regulated so far. The “Pick One of Two” behavior of e-commerce platforms not only destroys the fair competition order between platforms, but also damages the legitimate rights and interests of operators and consumers. In view of this, this paper analyzes the dual nature of e-commerce platform “Pick One of Two” behavior and the inadequacy of the theory of abuse of comparative advantage.