Circulating tumor cells (CTCs) are crucial biomarkers for cancer metastasis, prognosis, and treatment monitoring, but their rarity in peripheral blood and phenotypic heterogeneity pose significant challenges for isolation and analysis. Traditional capture methods, such as immunoaffinity and physical separation, often suffer from low sensitivity, loss of heterogeneous populations, and limited specificity. To overcome these limitations, biomimetic platforms using cellular membrane engineering have emerged as a promising alternative, improving both CTCs capture efficiency and functional integrity. Additionally, CTCs neutralization presents a potential strategy to prevent metastasis by disrupting survival mechanisms that facilitate immune evasion, such as interactions with platelets, endothelial adhesion, and microthrombus formation. Cellular membrane engineering not only aids in isolating CTCs but also neutralizes them by mimicking physiological interactions that interfere with these protective mechanisms. This chapter examines the biological characteristics and clinical significance of CTCs, explores current capture and neutralization strategies, and highlights the advantages of membrane-based biomimetic platforms. It discusses key advancements in membrane functionalization and their potential for both CTCs isolation and neutralization in clinical settings. Future research should focus on optimizing these platforms for clinical validation, improving reproducibility, and integrating microfluidic systems to enhance CTCs characterization and therapeutic interventions.