A research on direct thrust control loop design method of a turbofan engine was carried out. Firstly

an onboard model and a thrust estimator of turbofan engines were built based on unknown input observer(UIO) design. Accurate estimation of the entire flight envelope thrust was achieved through decoupling the external disturbance by the UIO observer. Secondly

an integrated dual-loop direct thrust control scheme was proposed. Respectively

its inner loop control was achieved through rotor speed close-loop control scheme

and its outer loop control through engine thrust close-loop control scheme. It is beneficial to realize the independent design of control parameters for each loop. At the end

disturbance rejection and servo tracking ability of the proposed control scheme was successfully validated by simulation. For the engine of different flight working condition points of the direct thrust control

the thrust control error is not more than 0.1%

the speed control deviation is not more than 0.2%.