This study aimed to explore the detailed molecular mechanism and biomarkers in spinal cord injury (SCI). Gene expression profiles of GSE125630 were downloaded from the Gene Expression Omnibus (GEO) database, and comprised 14 spinal cord tissues, including contusion SCI group (n = 6, unexercised), complete transection group (n = 4, unexercised), and uninjured control group (n = 4, unexercised). Differentially expressed gene (DEG) and time-series gene investigations, functional enrichment analysis, protein-protein interaction (PPI) network construction, characteristic gene-related disease analysis, and TF-target gene interaction studies were performed. A total of 122 DEGs and 409 DEGs were respectively identified in contusion SCI versus control group and complete transection versus control group, respectively. The PPI network investigated 16 characteristic genes including corticotropin-releasing hormone (CRH), tyrosine hydroxylase (TH), and neurotensin (NTS). These genes were mainly enriched in functions involving response to ethanol, corticosterone, and estradiol. Eventually, a TF-target gene interaction network was constructed with nine TFs [including activating transcription factor 3 (ATF3)] and 10 characteristic genes. The results indicate that regulation of osteoblast differentiation and positive regulation of the BMP signaling pathway may be suppressed in the process of SCI. TH may play a pivotal role in the progression of SCI. In addition, DEGs such as CRH and NTS may be novel targets for SCI therapy.