Psoriasis is a chronic inflammatory dermatological disorder characterized by immune dysregulation, oxidative stress, and elevated levels of circulating cell-free DNA. Although systemic or topical immunosuppressants remain the cornerstone of psoriasis management, conventional therapeutic strategies are hindered by several limitations, including suboptimal drug delivery efficiency, off-target adverse effects, and poor patient adherence. Recently, microneedle (MN) technology has emerged as a transformative approach for psoriasis treatment and diagnosis, leveraging its unique advantages in targeted drug delivery and minimally invasive biomarker monitoring. This review provides a timely and comprehensive analysis of MN-mediated therapeutic and diagnostic strategies for psoriasis. First, we systematically elucidate the pathophysiological mechanisms underlying psoriasis. Subsequently, we explore the multifaceted applications of MNs in both therapeutic and diagnostic domains: (1) MNs enable the transdermal administration of diverse therapeutic agents, including small-molecule drugs, oligonucleotides, DNA-based therapies, monoclonal antibodies, inactivated viruses, and nanoparticles, offering enhanced precision in psoriasis treatment; (2) MNs facilitate minimally invasive extraction of disease-associated biomarkers from interstitial fluid, enabling real-time assessment of disease onset and progression. Finally, we critically evaluate the current challenges and future directions in this rapidly evolving field. We anticipate that this review will provide valuable insights to guide further advancements in MN-based technologies for optimized psoriasis management.