Engineered algae microrobots, coated with genetically modified dendritic cell membranes, act as photosynthetic living materials to enhance T cell anti-tumor immunity. In a hypoxic tumor microenvironment, T cell activity is inhibited, limiting their ability to combat cancer. This study introduces a "photosynthetic micron robot" composed of Chlorella vulgaris microalgae and engineered dendritic cell membranes overexpressing TNF ligands OX40L, 4-1BBL, and CD70. These algae generate oxygen through photosynthesis, alleviating hypoxia and promoting T cell activation and proliferation. The TNF ligands on the algae's surface bind to T cell receptors, enhancing T cell function. When combined with a PD-1 inhibitor, the algae significantly prevent tumor relapse and metastasis in mice. The engineered algae not only improve oxygen levels but also stimulate the production of effector and memory T cells, enhancing anti-tumor immunity. The study demonstrates that this approach effectively reinvigorates exhausted T cells and suppresses tumor growth, offering a promising strategy for cancer immunotherapy. The algae-based system is biocompatible, safe, and capable of delivering therapeutic benefits through targeted oxygenation and immune modulation.Engineered algae microrobots, coated with genetically modified dendritic cell membranes, act as photosynthetic living materials to enhance T cell anti-tumor immunity. In a hypoxic tumor microenvironment, T cell activity is inhibited, limiting their ability to combat cancer. This study introduces a "photosynthetic micron robot" composed of Chlorella vulgaris microalgae and engineered dendritic cell membranes overexpressing TNF ligands OX40L, 4-1BBL, and CD70. These algae generate oxygen through photosynthesis, alleviating hypoxia and promoting T cell activation and proliferation. The TNF ligands on the algae's surface bind to T cell receptors, enhancing T cell function. When combined with a PD-1 inhibitor, the algae significantly prevent tumor relapse and metastasis in mice. The engineered algae not only improve oxygen levels but also stimulate the production of effector and memory T cells, enhancing anti-tumor immunity. The study demonstrates that this approach effectively reinvigorates exhausted T cells and suppresses tumor growth, offering a promising strategy for cancer immunotherapy. The algae-based system is biocompatible, safe, and capable of delivering therapeutic benefits through targeted oxygenation and immune modulation.