In the operation of civil aircraft at plateau airport， the climbing gradient is required to be high， and the load loss is serious. Therefore， it is of great significance to optimize the takeoff performance and increase the takeoff weight in terms of economic benefits. In this paper， based on theoretical analysis， the takeoff performance is optimized under the premise of meeting the airworthiness requirements by reducing the flap deflection or using the improved climb method， and the takeoff distances， acceleration stop distances， and takeoff weights of different flap configurations and different climb methods are calculated and analyzed. The results show that the effective optimization can significantly improve the takeoff weight and performance， also yield good economic returns.