Active disturbance rejection control system and control method for first-order pure lag object

The invention provides an active disturbance rejection control system and a control method for a first-order pure lag object. The active disturbance rejection control system comprises a control signal storage. The active disturbance rejection control system and the control method have the advantages that a control input variable of the controlled object can be acquired by the control signal storage, can be stored in the control signal storage, is delayed by preset time and then is outputted to an expanded state observer, so that an output variable of the controlled object does not correspond to the control input variable of a previous moment under the condition that lag of the output variable of the controlled object can be compensated; two input variables (the output variable of the controlled object and the control input variable of the previous moment) received by the expanded state observer can accurately correspond to each other, time directions of the two input variables of the expanded state observer can be unified, accordingly, the observation precision is improved, a closed-loop control effect is greatly improved, and active disturbance rejection control is stable and can be accurately performed on the first-order pure lag object.