The invention discloses a blending preparation of a chemical pesticide and a biological pesticide and an application thereof. In the blending preparation, the chemical pesticide is dimehypo, and the biological pesticide is one or more of Azadirachtin missible oil, rotenone missible oil, bacillus thuringiensis and Jinggangmycin. The blending preparation of the invention can obviously reduce the dosage of the chemical pesticide, increases the pesticide effect of the pesticides, reduces pesticide residues, lightens environment pollution and can enhance the resistance of rice so as to reach the purposes for increasing the yield of the rice and improving the quality of the rice, and the blending preparation can be mainly used for preventing and treating Cnaphalocrocis medinalis, Chilo suppressalis, tryporyza incertulas or banded sclerotial blight of the rice.