The invention relates to preparation of an electric control material and aims to provide a preparation method of an Ag-YAG electric control material. The preparation method comprises the following steps of: adding Y(NO3)3.6H2O and Al(NO3)3.9H2O in deionized water to be dissolved, and adding hexamethylenetetramine while stirring; performing a reaction for 70-100min at 85-100 DEG C to obtain a YAG sol; drying the YAG sol to form a dry gel; sintering the dry gel in an air atmosphere to obtain YAG powder; after mixing the YAG powder with Ag powder by way of ball milling, performing cold pressing and tabletting to prepare sheets; and sintering the sheets to obtain the electric control material. The Ag-YAG composite material obtained by the method can replace AgCdO and can solve the problem thatin the prior art, the preparation temperature of the YAG powder is high, and meanwhile, has the advantages of being simple in preparation process, low in cost and the like. The electric control material prepared by taking yttrium aluminum garnet as a reinforcing material has excellent mechanical properties and electric service life, and has a wide application prospect in the field of low-voltageapparatus. The synthesized YAG particles are of grain size controllable nanoscale, so that the electrical resistivity is reduced favorably and the mechanical properties are enhanced favorably.