Increased proliferation and migration of abnormal airway smooth muscle cells (ASMCs) are significantly associated with asthma. Recently, the function of long non-coding RNAs (lncRNAs) in ASMCs has been identified. Our research attempted to resolve the function of the lncRNA DGCR5 in ASMCs and focus on its in-depth mechanisms of proliferation and migration. Quantitative real-time PCR and western blotting were used to evaluate the expressions of RNA and proteins, respectively. The CCK-8 assay was used to detect cell proliferation. Transwell assays were used to assess migration. Luciferase and RNA pull-down assays were used to verify the targeting between miR-204-5p and lncRNA DGCR5 or SRSF7. LncRNA DGCR5 was upregulated in ASMCs stimulated with PDGF-BB. Knockdown of DGCR5 reversed the effect of platelet-derived growth factor BB (PDGF-BB) on the proliferation and migration of ASMCs. The results of this study showed that lncRNA DGCR5 binds to miR-204-5p, and SRSF7 is the target of miR-204-5p. Rescue experiments verified the interaction between miR-204-5p and DGCR5, as well as that between miR-204-5p and SRSF7. Overall, this study revealed that the lncRNA DGCR5/miR-204-5p/SRSF7 signalling axis has key regulatory effects on the proliferation and migration of ASMCs.