The invention discloses a generator set location scheme optimization method for reducing frequency spatial-temporal distribution. Optimization for different generator set location schemes is performed. The method comprises the steps: making an expected scheme: two or more schemes are provided under the condition of meeting the basic operation constraint of the electric power system and the load growth demand in the future; setting the system disturbance; defining the spatial-temporal distribution indexes: four spatial-temporal distribution indexes of the frequency change rate, the response delay, the maximum frequency offset and the maximum offset delay are defined; selecting the observation points; calculating the assessment indexes: the observation points are grouped, difference and de-unitization processing is performed on the mean of two groups of the spatial-temporal distribution indexes, then the spatial-temporal distribution target value under a certain fault is obtained throughweighted summation, and equal proportional weighted summation is performed on the spatial-temporal distribution target values under different faults so as to obtain the final target value; and selecting the optimal scheme. The insufficiency in the aspect of frequency spatial-temporal distribution in the problem of set location can be compensated so that the rationality of the set location schemecan be guaranteed.