To obtain the sequence information of salt-tolerant genes in castor bean， we conducted a study to explore differentially expressed genes and related metabolic pathways under salt stress. We used seedling leaves of castor bean （cultivar Tongbi No. 5） treated with salt stress （300 mmol/L NaCl） for 0， 12， and 24 hours as experimental materials. Transcriptome sequencing analysis was performed using high-throughput sequencing technology. The results showed that there were 4822 and 3103 differentially expressed genes at 12 and 24 hours of salt stress， respectively. Co-expression pattern clustering analysis was conducted on the shared 1872 differentially expressed genes， and three expression patterns were identified. KEGG pathway analysis revealed significant enrichment of three pathways， namely valine， leucine， and isoleucine degradation （ko00280）， plant circadian rhythm regulation （ko04712）， and starch and sucrose metabolism （ko00500）， in the adaptation process to salt stress. GO functional enrichment analysis showed that most differentially expressed genes were enriched in biological processes， with the highest enrichment in cellular processes （GO：0009987） and response to non-biological stress （GO：0009628）. In addition， a total of 19 transcription factors were found to be involved in the salt stress response of castor bean. In the plant hormone signal transduction pathway， 42 differentially expressed genes were identified， with 97.6% of genes showing upregulated expression at 12 and 24 hours. Furthermore， we identified differentially expressed genes involved in photosynthesis， antioxidant regulation， and Na⁺， K⁺， and Ca²⁺ transport related to salt stress in castor bean seedlings. qRT-PCR results confirmed the reliability of the above experimental results. In conclusion， this study provides a theoretical basis for the exploration of salt-tolerant genes and the analysis of salt stress adaptation mechanisms in castor bean.