The invention relates to a compound suspending agent of difenoconazole, propiconazole and pyraclostrobin and a preparation method thereof, and relates to the technical field of crop bactericidal compositions. At least 10 part of difenoconazole, 10 part of propiconazole, 10 part of pyraclostrobin, 3 parts of fatty alcohol polyoxyethylene ether, 5 parts of styryl phenol polyoxyethylene ether, 0.5 part of xanthan gum, 0.5 part of sodium benzoate, 0.5 part of defoaming agent and deionized water supplemented to 100 part. The raw materials are pumped into the batching kettle, mixed and stirred, and then preliminarily ground by colloid mill, then finely ground by sand mill, sampled and analyzed, filtered, measured, packaged and put into storage after inspection. In the invention, 30% difenoconazole, propiconazole and pyraclostrobin compound suspending agent are mixed in a ratio of10:10, so that an obvious synergistic action range can be achieved, while other mixed preparations cannot achieve the obvious synergistic action range.