Background: High-grade muscle-invasive bladder cancer (MIBC) is a severe malignancy characterized by aggressive behavior and poor prognosis. Traditional treatment options, including radical cystectomy and systemic chemotherapy, often yield limited success and significant side effects, negatively impacting patients' quality of life.Objective: This study aims to review recent advancements in immunotherapeutic strategies for the treatment of high-grade MIBC, focusing on the efficacy of immune checkpoint inhibitors (ICIs), the role of molecular subtyping in personalized therapy, and the potential of combination therapies. Methods: A comprehensive review of current literature was conducted, analyzing the effectiveness of ICIs like pembrolizumab and atezolizumab in MIBC treatment. The study also explored ongoing research into molecular subtypes and combination therapies.Results: Immune checkpoint inhibitors have shown promising results in enhancing the immune system's ability to target and eliminate tumor cells in MIBC. The identification of molecular subtypes allows for personalized treatment approaches, while combination therapies offer the potential to improve treatment efficacy.Conclusion: Immunotherapy has significantly altered the treatment landscape for high-grade MIBC, offering new hope for improved patient outcomes. However, challenges such as treatment-associated toxicities and the need for predictive biomarkers remain, necessitating further research to optimize these strategies.