The invention discloses a power 
system load modelling method, including the steps that: A, load classification based on daily 
active load curve; B, load modelling based on statistic synthesis method; C, 
load model parameter 
sensitivity analysis and 
range analysis based on 
simulation analysis; D, 
load model parameter node identification based on 
genetic algorithm, namely node identification is carried out by taking fitted local disturbance data as target, setting low sensitivity parameter value as statistic synthesis method surveying parameter value and adopting the 
genetic algorithm, so as to obtain multiple groups of 
load model parameters; E, load 
model parameter wide area check based on WAMS, namely load 
model parameter check is carried out by taking the multiple groups of solutions identified by node as initial value and taking accurate fitting on 
system wide area dynamic characteristic as target, so as to obtain unique solution capable of reflecting 
wide area dynamic characteristic when 
system is subject to disturbance. The invention solves the problems of multiple solutions and 
identifiability of overall measuring identifying method by load point classification and load 
model parameter aggregation and has popularization and application values.