Abstract: A steady state and transition state multi-variable control method of a turbofan engine based on an active disturbance rejection control theory (ADRC) belongs to the technical field of aero-engine control. Firstly, multiple groups of manipulated variables and controlled variables of a turbofan engine are preliminarily selected, and then the manipulated variables and controlled variables with high correlation are further determined by a correlation analysis method. Each group of control instructions is planned as a tracking trajectory by using a tracking differentiator, and is used as the input of a nonlinear proportional-differential controller together with the current state estimated by the extended state observer to calculate the manipulated variables.