The invention relates to a suspension concentrate for seed coatings and particularly relates to a three effective component (pyraclostrobin, phenazine-1-carboxylic acid and thiamethoxam) containing compound suspension concentrate for seed coatings as well as a preparation method and application thereof, wherein the three effective component containing compound suspension concentrate is a second-generation high-efficiency low-toxicity nicotine containing insecticide, and the mass ratio of pyraclostrobin, phenazine-1-carboxylic acid and thiamethoxam is (1-80):(80-1):(1-80). The suspension concentrate has special effects, is mainly used for preventing and treating wilt, rhizoctonia solani induced blight, green sickness, damping off, rhizoctonia solani induced blight, seedling rot, sclerotinia, phytophthora diseases, dry rot, scab, sclerotial soft rot, seedling blight, stem blight, leaf blight, root rot and continuous cropping obstacle of cereals with special effects and has significant effects of preventing and treating pests such as aphids, leafhoppers, thrips, whiteflies, potato beetles and wheat bulb flies. In addition, the insecticidal and bactericidal compound suspension concentrate for seed coatings can significantly improve the insect and disease resisting capacity of spouts and seedlings and has the functions of promoting the growth and development of crop roots, strengthening seedlings and increasing the survival rate of seedlings.