Astragalus membranaceus seed coating agent suitable for dry farmland

The invention discloses an astragalus membranaceus seed coating agent suitable for dry farmland. The astragalus membranaceus seed coating agent comprises the following components in percentage by weight: 16-21% of a bactericide; 18-24% of an insecticide; 0.02-0.05% of copper sulfate; 0.04-0.06% of brassin; 7-11% of humic acid; 22-27% of a water-retaining agent; 0.1-0.2% of a pigment; and the balance filler. Specifically, the bactericide is composed of carbendazim and thiram in a weight ratio of 1:1.25-1:2.15; the insecticide is composed of thiamethoxam and imidacloprid in a weight ratio of 1:1.2-1:2.15; the water-retaining agent is a starch grafted acrylate polymerization cross-linked product; and the components are mixed uniformly to obtain the product. The astragalus membranaceus seed coating agent can be used in arid areas with less rain, can retain water and seedlings and promote seed germination, can effectively prevent diseases and inhibit insect pests, has no negative effect onastragalus membranaceus s