Seaweed extracts have been extensively studied as plant growth regulators and stress tolerance inducers. However, the molecular mechanism of sweet corn plants responsive to the treatment with an Ascophyllum extract remains unknown. To investigate the role of seaweed extract as a regulator in plants and explain its possible physiological, transcriptomic, and metabolic response mechanisms, we investigated the physiological properties and mRNA and metabolite expression profiles of sweet corn in response to "Yi nuo" fertilizer, a new biostimulant. Physiological analyses revealed that chlorophyll content, PPO and PAL activities, the contents of N, P, and K elements, plant hormones, and yield were significantly increased in the new biostimulant treatment group. Metabolomics analysis indicated that the accumulation of some plant growth-related, development-related, and stress-related differentially expressed metabolites were increased, such as glutathione, proline, chlorogenic acid, glutamate, and gibberellin A 3 . RNA-seq found that the expression of many important DEGs, including GID1, DELLA, TGA, MYC2, BAK1, Psb28, PsbA, etc., was changed. Comprehensive analysis revealed that the gibberellin synthesis and phenylpropanoid and flavonoid biosynthesis pathways have different expression and accumulation patterns, including the key DEMs�GA 3 and chlorogenic acid. These results obtained using a multiomics approach explore the plant response to biostimulants obtained from the seaweed Ascophyllum from a molecular perspective.