Flax (Linum usitatissimum L.) is an important oilseed crop widely cultivated for its oil and fiber. This study conducted transcriptome analysis to analyze the gene expression profiles of roots, leaves, stamens, pistils, and fruits in the flax cultivar Longya10. A total of 43,471 genes were detected in the RNA-seq data, with 34,497 genes showing differential expression levels between different organs. Gene expression patterns varied across different organs, with differences observed in expression-regulating genes within specific organs. However, 23,448 genes were found to be commonly expressed across all organs. Further analysis revealed organ-specific gene expressions, with 236, 690, 544, 909, and 1212 genes identified in pistils, fruits, leaves, roots, and stamens, respectively. Gene Ontology (GO) enrichment analysis was performed on these organ-specific genes, and significant enrichment was observed in various biological processes, cellular components, and molecular functions, providing new insights for the specific growth patterns of flax organs. Furthermore, we investigated the expression differences of AP2 transcription factors in various tissues and organs of Longya10. We identified 96 AP2 genes that were differentially expressed in different organs and annotated them into various biological pathways. Our results suggest that AP2 transcription factors may play important roles in regulating the growth and development of flax organs including stress response. In summary, our study provides a comprehensive analysis of gene expression patterns in different organs and tissues of flax plant and identifies potential critical regulators of flax organ growth and development. These findings contribute to a better understanding of the molecular mechanisms underlying flax organ development and may have important implications for the genetic improvement of flax crops.