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The use of secondary metabolites of rice to control pests has become a research hotspot, but little is known about the mechanism of rice self-resistance. In this study, metabolomics analysis was performed on two groups of rice (T1, with insect pests; T2, without pests), indicating that fatty acids, alkaloids, and phenolic acids were significantly up-regulated in T1. The up-regulated metabolites (<i>p</i>-value < 0.1) were enriched in linoleic acid metabolism, terpene, piperidine, and pyridine alkaloid biosynthesis, α-linolenic acid metabolism, and tryptophan metabolism. Six significantly up-regulated differential metabolites in T1 were screened out: <i>N</i>-<i>trans</i>-feruloyl-3-methoxytyramine (<b>1</b>), <i>N</i>-<i>trans</i>-feruloyltyramine (<b>2</b>), N-<i>trans</i>-<i>p</i>-coumaroyltyramine (<b>3</b>), <i>N</i>-<i>cis</i>-feruloyltyramine (<b>4</b>), <i>N</i>-phenylacetyl-L-glutamine (<b>5</b>), and benzamide (<b>6</b>). The insect growth inhibitory activities of these six different metabolites were determined, and the results show that compound <b>1</b> had the highest activity, which significantly inhibited the growth of <i>Chilo suppressalis</i> by 59.63%. Compounds <b>2</b>–<b>4</b> also showed a good inhibitory effect on the growth of <i>Chilo suppressalis</i>, while the other compounds had no significant effect. RNA-seq analyses showed that larval exposure to compound <b>1</b> up-regulated the genes that were significantly enriched in ribosome biogenesis in eukaryotes, the cell cycle, ribosomes, and other pathways. The down-regulated genes were significantly enriched in metabolic pathways, oxidative phosphorylation, the citrate cycle (TCA cycle), and other pathways. Eighteen up-regulated genes and fifteen down-regulated genes from the above significantly enriched pathways were screened out and verified by real-time quantitative PCR. The activities of detoxification enzymes (glutathione S-transferase (GST); UDP-glucuronosyltransferase (UGT); and carboxylesterase (CarE)) under larval exposure to compound <b>1</b> were measured, which indicated that the activity of GST was significantly inhibited by compound <b>1</b>, while the activities of the UGT and CarE enzymes did not significantly change. As determined by UPLC-MS, the contents of compound <b>1</b> in the T1 and T2 groups were 8.55 ng/g and 0.53 ng/g, respectively, which indicated that pest insects significantly induced the synthesis of compound <b>1</b>. Compound <b>1</b> may enhance rice insect resistance by inhibiting the detoxification enzyme activity and metabolism of <i>Chilo suppressalis</i>, as well as promoting cell proliferation to affect its normal growth and development process. The chemical–ecological mechanism of the insect resistance of rice is preliminarily clarified in this paper.