The invention relates to a suspending agent sterilizing two-spotted spider mite Bacillus thuringiensis, belonging to the field of biological pesticides. The suspending agent is prepared by mixing fermentation liquid of the Bacillus thuringiensis BtR05 with a surfactant, an antiseptic agent, a suspending auxiliary agent and a thickening agent, wherein, the suspending auxiliary agent is ammonium sulphate. The invention also provides preparation methods and uses of the suspending agent, the suspending agent prepared by the BtR05 bacterium and the fermentation liquid of the bacterium is quite poisonous against two-spotted spider mite, American white moth, diamond-back moth, chive maggot, grub, maggot galerucella and Meloidogyne incognita, which is an efficient and broad-spectrum biological pesticide.