Immunotherapy is a cancer therapy by enhancing T cell activity. Immune checkpoint, like PD-1/PD-L1, is a key mechanism to regulate T cell activity. The drugs for disrupting the PD-1-PD-L1 interaction are the present promising cancer therapy strategy. Current immunotherapy results in clinical trials show significant improvement in the survival rate in melanoma and lung cancer. However, Due to the high price of immunotherapy reagents, it is challenging to use preclinical experiments to find the appropriate drug dosage. Therefore, here we developed a microfluidic device combined with the following features. The first is highly biocompatible porous photo-initiated cross-linked hydrogel (GelMA) as a 3D culture model to mimic tumor tissue environment. The second is the peripheral channels to stimulate the immune cell environment in blood vessels. The third is the concentration gradient generator to achieve high-throughput multiple drug concentration testing. The results verified that cells could survive in GelMA, and the T cells could infiltrate into GelMA containing cancer cells. Furthermore, this Labchip can simultaneously detect the effects of three doses of drug counterparts on immune cells.