The invention discloses a special seed dressing agent with effects of increasing the survival rate and invigorating seedlings for sweet corn. The seed dressing agent comprises gamma-aminobutyric acid, matrine, thiamethoxam, sedaxane, carboxin, amino-oligosaccharin, salicylic acid, glycine betaine, choline chloride, fulvic acid, starch grafted potassium acrylate, calcium chloride, a wetting dispersant, an emulsifier, gibberellin and microelement water soluble fertilizer mother liquor. Under normal conditions or adverse conditions of drought, low temperature and the like, the seed dressing agent has an obvious effect of improving the seed vigor and seedling quality of the sweet corn, can be used for effectively increasing the yield of the fresh spike of the sweet corn, also has effects of exterminating underground insects, protecting and invigorating seedlings and preventing and treating main plant diseases and insect pests of the corn, has control efficiency up to 70%-90% for plant diseases and insect pests in a seedling stage, has control efficiency up to 87%-96% for corn head smut, and not only can help farmers to save labor cost and seed cost greatly, but also can increase the yield by 15%-20%, thus having excellent social and economic benefits and application prospects.