This paper studies the airline's strategy of ticket selling on its own website or through other distribution channels,and discusses the optimal pricing strategy when there are Online Travel Agency( OTA) platforms. Travelers are divided into“loyal”and“disloyal”ones; the airline is supposed to maximize its profit by setting optimal ticket prices and rebates,while the OTA would accordingly set the optimal price according to the travelers' demand and the airline's decision. The results reveal that the sensitivity of airline travelers' demand to price is larger than that of the OTA platform's travelers'; The airlines are less likely to join the OTA platform if they have a large loyal consumer base or the OTA platform is more competitive; The airline market will achieve a state of equilibrium when there are a certain number of airlines on the OTA platform. Numerical results are presented for the model validation.