Abstract: Under twin variable control with the equal low compressor speed and equal low turbine exit temperature,the twin spool turbojet can obtain higher power performance.In this paper,firstly,the engine dynamic model with two inputs and two outputs is deduced.Then with the aid of LQR theory,the optical regulator of twin variable control system is designed,and the approaches for processing some problems existed in the design process are recommanded.Finally,the control system designed in terms of optical method is simulated numerically.The results show that,in the condition of a state perturbantion on the system,the transient performance of the system recovered to original state is more satisfactory,and the variation of control mediators is in allowable limits of the controllers.