The present invention provides a beauveria bassiana oil suspending agent and relates to the field of microorganism pesticides. The beauveria bassiana oil suspending agent is obtained by adding beauveria bassiana spores into a mixture of a surfactant and solvent oil to be mixed evenly. A spore concentration is 9-11 billion/mL. The beauveria bassiana oil suspending agent also contains 5-10 g/L of trehalose, 2-8 g/L of glycerin and 0.2-1 g/L of xanthan gum. The beauveria bassiana oil suspending agent significantly improves heat resistance of the beauveria bassiana spores, and can be used for preparation, preservation and field application of beauveria bassiana preparations.