Robust flight control laws based on back-stepping technology and ADRC method are designed for attitude control of a non-linear aircraft system. First, non-linear aircraft model is introduced and converted to standard equation of state. Then, the extended state observer is applied to estimate the unknown variables, the homologous ADRC is designed to ensure the state variables of the CLS to astringe to the reference state. Next, the stability of ESO and ADRC are analyzed and proven theoretically. At last, the effectiveness of this method is illustrated by extensive comparative simulations. The results acquired from simulation attest that ADRC can achieve better control performance than PID and SMC method.