The invention relates to a pesticide composition for preventing and controlling nematodiasis. The pesticide composition is prepared from fosthiazate, bacillus subtillis, auxiliaries and filler, wherein fosthiazate and bacillus subtillis are used as effective constituents, the weight ratio of fosthiazate to bacillus subtillis is 20:1-2:1, and the auxiliaries and the filler can be accepted on the aspect of pesticide. A dispersing agent, a wetting agent, a disintegrating agent and/or a binding agent serve as the additives. The effective constituents, namely, fosthiazate and bacillus subtillis, account for 10-20% of the weight of the pesticide composition. The dosage form of the pesticide composition is the water dispersible granule form. The pesticide composition has the advantages that efficiency and low toxicity are achieved, the use amount of pesticide is decreased, pesticide residues are reduced, and soil acidification is prevented.