The invention discloses an improved dispersion absolute value and criterion based power load combination predication method. The method includes: adopting m single predication models for predication of a historical data sequence of power load; calculating predication precision to obtain a predication precision sequence; calculating an IOWGA operator combination predicated value; calculating a combination fresh dispersion absolute value Jt; establishing an improved dispersion absolute value and criterion based combination predication model, and solving the model to obtain a weighting coefficient of each single predication model; calculating a medium and long term power load predicated value and the like. The method has advantages that on the basis of improved dispersion absolute values and criterions, predication precision of each single predication method in different time is taken into full consideration, and consequently a weighting coefficient of the combination model varies along with predication precision of different moments, and the combination predication model is enabled to be dynamic; by introduction of a fresh degree function, the defect that predication precisions at different historical stages are not treated differently is overcome, and high accuracy in medium and long term power system load predication is achieved.