The invention provides an optimization method and device for a draught fan electromagnetic transient recovery characteristic curve. The method comprises the following steps that: firstly, determiningthe electromagnetic transient recovery characteristic curve and the electromechanical transient recovery characteristic curve of wind power generation equipment when a power grid is subjected to unsymmetrical faults, and preprocessing the electromagnetic transient recovery characteristic curve according to the electromechanical transient recovery characteristic curve; and then, according to a pre-constructed optimization model, selecting the key data point of the preprocessed electromagnetic transient recovery characteristic curve. By use of the method, the key data point is selected to realize the optimization of the electromagnetic transient recovery characteristic curve, the length of the electromagnetic transient recovery characteristic curve is reduced, so that a single sample occupies small storage space so as to be suitable for optimizing a great quantity of electromagnetic transient recovery characteristic curves, and the optimized curve is stored in a electromagnetic transientrecovery characteristic curve sample library so as to meet the requirements on researching recovery characteristics under other faults and working conditions.