Substituted pyrimidines as pharmaceuticals and insecticides

The compound shown as the general formula I has broad-spectrum bactericidal and insecticidal activity in the field of agriculture. The compound shown as the general formula I has a good prevention effect on various germs such as cucumber downy mildew, wheat powdery mildew, puccinia sorghi, rice blast and cucumber gray mold, and particularly, still has the good prevention and control effect on the cucumber downy mildew, the puccinia sorghi and the wheat powdery mildew at a lower dosage. At the same time, a part of compound has better insecticidal activity, and can be used for preventing and controlling various insect pests such as diamondback moths, myzus persicae, armyworms and tetranychus cinabarinus boisdu.