Adoptive T cell therapy is a promising cancer treatment but faces challenges in selecting antigen-specific T cells and isolating cells based on receptor avidity. Traditional methods, such as Dynabeads, are static and often lead to non-specific enrichment, reducing therapeutic efficacy. In contrast, we developed a dynamic microfluidic screening system that achieves two major breakthroughs: enhanced specificity and avidity-based T cell isolation. The first breakthrough enhances specificity by utilizing intracellular hydrogelation technology to preserve intact cell membranes and mimic the immunological synapse. This ensures precise enrichment of high-affinity T cells. Additionally, the microfluidic system applies shear stress to remove temporary bonds from non-cognate T cells, further improving specificity. The second breakthrough isolates T cells based on receptor avidity. By applying controlled flow rates and shear stress, the system dynamically separates T cells with varying binding strengths. This allows for the identification of subsets with optimal therapeutic potential while addressing safety concerns such as autoimmunity and exhaustion. Unlike static methods, this platform provides real-time selection and scalability. It improves specificity and enables avidity-based selection, overcoming key limitations in current protocols. This dynamic system offers significant advancement for adoptive T cell therapy, particularly in solid tumors where infiltration and specificity remain challenging.