Under stress conditions, plants are highly susceptible to both biotic and abiotic stresses, which can impede growth and disrupt development. Upon encountering these stresses, plants activate cascade transcriptional responses, initiating key genes and regulatory networks to form core survival strategies for adapting to harsh environments. Transcriptomics, as a research methodology, effectively deciphers transcriptional response strategies in plants under diverse environmental challenges. This chapter begins by introducing several cutting-edge technologies for studying plant stress responses, including RNA-Seq, microarray-based transcriptomics, comparative transcriptomics, single-cell transcriptomics, Iso-Seq, and qPCR. It also elaborates on experimental design and analytical methodologies for transcriptomic studies. The focus lies on the role of transcriptomics in identifying stress-responsive genes and the regulatory mechanisms of alternative splicing (AS) during stress adaptation. By leveraging third-generation sequencing technologies, the chapter systematically reveals structural variations in stress-induced full-length transcripts, novel non-coding RNAs (lncRNAs), and functional roles of complex gene models in stress adaptation. Future applications of transcriptomics in deciphering plant stress responses are also prospected. This work provides a systematic understanding of transcriptomics in plant stress responses and offers novel insights to guide its future development in stress resilience research.