Intrauterine adhesion (IUA) poses a serious threat to women's health, and its specific pathogenesis has not yet been elucidated. Our study found through high-throughput sequencing that differentially expressed genes of the endometrial tissues from healthy individuals or IUA patients were enriched in the toll-like receptor (TLR), nuclear factor-kappa B (NF-kB), and nucleotide-binding oligomerization domain-like receptor (NLR) signaling pathways. Meanwhile, we observed that compared to the controls, long non-coding RNA (lncRNA) growth arrest-specific transcripts 5 (GAS5) was significantly upregulated in the endometrial tissue of IUA patients and scratching/lipopolysaccharide (LPS)-induced IUA model mice. Subsequently, results from the functional verification assay, including hematoxylin-eosin staining, enzyme-linked immunosorbent assay, and western blot, showed that knockdown of GAS5 improved endometrial injury and uterine adhesions, decreased the levels of TIMP1, α-SMA, Vimentin, and COL1A1, but elevated MMP9 level to reduce excessive accumulation of extracellular matrix (ECM), and inhibited the expression of NLRP3, cleaved caspase-1, GSDMD, and nuclear p65 to ameliorate pyroptosis in IUA model mice. As confirmed by bioinformatics analysis and dual luciferase reporter gene system, GAS5 sponged microRNA (miR)-205-5p to upregulate TLR4, further activating the NF-kB and NLRP3 signaling in endometrial stromal cells (ESCs). The in vitro functional recovery experiments suggested that GAS5 knockdown alleviated LPS-induced activation of the NF-kB and NLRP3 signaling, pyroptotic cell death, and ECM deposition in ESCs, which was counteracted by overexpressing TLR4 and NLRP3. In a word, our study proved that targeting the GAS5/TLR4/NLRP3 signaling cascade inhibits ESCs pyroptosis and prevents the progression of IUA, providing promising therapeutic strategies for IUA disease.